Florida Department of Transportation Transportation Statistics Office

Transcription

1 Florida Department of Transportation Transportation Statistics Office

2 Traffic Monitoring Handbook Table of Contents A companion handbook focuses on Survey Processing Software (SPS) applications detailing the procedures and functions discussed in this document. This handbook is structured to provide the reader with a background in the terminology common to the traffic data collection profession. Once the terms and acronyms are understood, we proceed to describe the process from preparing to collect the data through the compilation of the annual report. While comprehensive in nature this handbook will constantly be re-evaluated and updated as necessary to include technological advances that have been evaluated and approved by the Department as well as improvements suggested by users from their valuable field perspective and experiences.

3 Traffic Monitoring Handbook To Navigate the documents using Adobe Acrobat Reader: Click back arrow to see last viewed page Click bottom X to close document without closing Acrobat Reader Use Bookmarks to view topics Turn Pages by clicking on scroll bar Click on VIDEO for additional information about topic. Close Windows Media Player when finished. Click on photos to view full screen, then click Return button The latest Windows Media Player update may have to be downloaded from Microsoft. Simply click YES when prompted to update. Videos are optimally viewed using 800x600 monitor setting. If Adobe Acrobat Reader 5.0 is already installed, Open Reader before inserting CD-ROM for faster page viewing. Florida Department of Transportation Transportation Statistics Office

4 Table of Contents 139BTable of Contents I. PURPOSE...6 II. OVERVIEW...6 III. SCOPE...6 IV. ABBREVIATIONS AND DEFINITIONS...7 V. SHORT-TERM PROGRAM...21 SHORT-TERM MONITORING SITES SAFETY PROCEDURES FOR TRAFFIC COUNT PERSONNEL SITE SELECTION TYPE OF COUNT, COLLECTION PERIODS AND DURATIONS VI. CONTINUOUS MONITORING PROGRAM...34 VOLUME MONITORING SITES SPEED MONITORING SITES CLASSIFICATION MONITORING SITES WEIGH-IN-MOTION SITES VII. WEEKLY DATA PROCESSING...36 PROCESSING OF SHORT-TERM COUNT DATA ANALYZING THE DATA MAINTAINING EFFICIENCY AND ACCURACY TRAFFIC CHARACTERISTICS INVENTORY DATABASE VIII. ANNUAL DATA PROCESSING...56 CONTINUOUS COUNT DATA FACTOR CATEGORIES ESTIMATES ANNUAL STATISTICS SECTION BREAK STATISTICS ROLLOVER DATA DISTRIBUTION IX. TTMS/PTMS Field Inspection and Inventory...62 Field Inspections of Traffic Monitoring Sites Sensor Configurations Cabinet Inspection Check Loops Check Piezos Check Communications (TTMS Sites Only) Check Power Backplane Check Counter Final Re-Check X. Reference Manuals...73 Traffic Monitoring Handbook Page 4 of 104 8/31/07

5 Table of Contents X. Appendicies APPENDIX A Traffic Monitoring Equipment Certification APPENDIX B FHWA Classification Scheme F APPENDIX C Standard Index Loop Installation Details APPENDIX D Standard Index Cabinet Installation Details APPENDIX E Standard Index Traffic Monitoring Site Details APPENDIX F AADT Development Flowchart APPENDIX G FDOT Quality Assurance Monitoring Plan APPENDIX H TTMS Inspection & TTMS Inventory Sheets Table of Videos Video 1 Introduction to Handbook... 6 Video 2 Site Selection Video 3 Equipment Video 4 Safety Procedures Video 5 Traffic Break Example Video 6 Site Selection Basics Video 7 Load SPS Video 8 Edit SPS Video 9 Upload Data Video 10 Manual Data Entry Video 11 Station Identification Video 12 Station Per Roadway Video 13 Station Counts Video 14 Volume Statistics Video 15 AADT History Video 16 Monthly ADT Video 17 Class Detail Video 18 Vehicle Statistics Video 19 Vehicle History Video 20 Seasonal Factor Video 21 Axle Factor Video 22 Seasonal Factors Video 23 Axle Factors Video 24 Resubmit Load Video 25 Traffic Breaks Video 26 Station Inventory Report Video 27 AADT History Report Video 28 Raw Counts Report Video 29 Monthly Continuous ADT Report 54 Video 30 Traffic Flow Breaks Video 31 AADT Development Video 32 Process Overview...62 Video 33 Check Conditions...64 Video 34 Check Pullbox Video 35 Cabinet Inspection Video 36 Measure Ground Rod Video 37 Record GPS Video 38 Check Loops Video 39 Check Piezos Video 40 Check Communications Video 41 Check Power Video 42 Check Wiring Harness Video 43 Check Counter Video 44 Final Re-Check Traffic Monitoring Handbook Page 5 of 104 8/31/07

6 I. Purpose TRAFFIC MONITORING HANDBOOK I. PURPOSE Video 1 Introduction to Handbook The Florida Department of Transportation (the Department) conducts traffic surveys to determine the volumes and types of vehicles and the weight of trucks using the highway network of Florida. Traffic surveys provide information essential to the general administration of highway programs. Traffic data are fundamental to determining vehicle miles of travel, project design parameters, highway classification, and the level of service provided by a highway facility. The Department conducts an Annual Traffic Count program to obtain traffic surveys, process raw counts, and maintain current and historic databases for the State Road System. The Annual Traffic Count Program is supplemented with additional counts that are performed as needed for special purposes. This handbook offers guidelines and techniques on Traffic Data Collection and Processing for the Department s Annual Traffic Count Program. Refer to the TRAFFIC MONITORING GUIDE (published by the US Department of Transportation, Federal Highway Administration, Office of Highway Policy Information) for recommendations regarding basic program structure, and suggestions to help improve and advance current traffic monitoring programs. II. OVERVIEW The traffic data collection program at the Florida Department of Transportation is a collaborative effort involving the Districts and the Transportation Statistics (TRANSTAT) Office. In broad terms, the Districts are responsible for collecting the short term coverage counts, defining the traffic segment breaks, keeping the station inventory file updated, and defining the factor categories. The TRANSTAT Office is responsible for operating the continuous traffic monitoring and weigh-in-motion programs, setting policy, maintaining the traffic databases and developing the AADT estimates. III. SCOPE All highway agencies collect the same basic types of data, and each can benefit from using a similar basic data collection framework. This guideline is used by the Central and District Offices as well as their consultants and contractors performing traffic surveys for FDOT use. It may also be used by Local governments and other agencies. Traffic Monitoring Handbook Page 6 of /30/07

7 IV Abbreviations and Definitions IV. ABBREVIATIONS AND DEFINITIONS ANNUAL AVERAGE The total volume of traffic on a highway segment for one year, DAILY TRAFFIC (AADT) divided by the number of days in the year. This volume is usually calculated by adjusting a short-term traffic count with seasonal (weekly) factors obtained from continuous monitoring sites. AADT is measured at continuous monitoring sites. ANNUAL AVERAGE WEEKDAY TRAFFIC (AAWDT) The estimate of typical traffic during a weekday (Monday through Friday) calculated from data measured at continuous monitoring sites. ASCENDING DIRECTION The direction of travel from the beginning milepost toward the ending milepost on a roadway section. The ascending direction is usually North or East. (See DESCENDING DIRECTION and ROADWAY SECTION) AUTOMATIC TRAFFIC RECORDER (ATR) See CONTINUOUS MONITORING SITE. AVERAGE DAILY TRAFFIC (ADT) AXLE ADJUSTMENT FACTOR The total traffic volume during a given time period (more than a day and less than a year) divided by the number of days in that time period. This volume is NOT adjusted for seasonal variations in traffic. See AXLE CORRECTION FACTOR. AXLE CORRECTION FACTOR (AF or ACF) The factor developed to adjust-axle counts into vehicle counts. Axle Correction Factors are developed from classification counts by dividing the total number of vehicles counted by half the number of axles on these vehicles. AXLE COUNTS ADT s that are obtained by equipment that counts axles and divides by two to estimate the total number of vehicles. This type of count ignores the fact that many vehicles have more than 2 axles. BIN A term used to identify categories into which data from traffic surveys are stored in the counter. For instance, axle classification volumes are sorted and stored in 13 bins (categories) according to FHWA Classification Scheme F. BREAK POINT (BREAK) A point on the roadway where significant changes in traffic volumes and vehicle classifications occur. It is described by a milepost. A break is always located at the beginning and ending of each Roadway Section, and at mileposts within the Roadway Section where significant changes in traffic volumes and vehicle classifications occur. (Also see SECTION BREAK) CENTRAL OFFICE (CO) See TRANSPORTATION STATISTICS OFFICE Traffic Monitoring Handbook Page 7 of /30/07

8 IV Abbreviations and Definitions CHANNEL A channel equates to a port into a counter. For example, a classification count requires a channel for every lane classified, but an axle or vehicle volume count only requires one channel for each road tube utilized (at least one channel for a two-way count or two channels for a directional count). CITY STREET SYSTEM Roads and streets that are owned by the cities and municipalities. CLASSIFICATION COUNT A traffic survey that counts the number of vehicles in each vehicle classification category. (See FHWA CLASSIFICATION SCHEME F.) CONTINUOUS MONITORING SITE Traffic counters that are permanently placed at specific locations throughout the state to record the distribution and variation of traffic flow by hour of the day, day of the week, and month of the year from year to year and transmit the data to the TRANSTAT Office via telephone lines. These sites record traffic volumes 24 hours a day, seven days a week. COUNT The data collected as a result of measuring and recording traffic characteristics such as vehicle volume, classification, speed, weight, or a combination of these characteristics. COUNTER Any device that collects traffic characteristics data. FDOT utilizes Continuous Counters, Classification and Weigh-In-Motion (WIM) Counters, Portable Axle Counters, and Portable Vehicle Counters. COUNTY HIGHWAY SYSTEM Roads owned by the counties, including some roads that pass through urban areas. COVERAGE COUNTS The basis purpose of the Short Term Count Program is to provide wide geographic coverage required by HPMS and ensure that upto-date traffic data exists for all roads maintained by FDOT. (see HIGHWAY PERFORMANCE MONITORING SYSTEM) CROSS-REFERENCE A method of assigning specific traffic data (such as truck percentage) from one count site to another. D FACTOR D is the directional distribution factor. (Also see FACTOR and DIRECTIONAL DISTRIBUTION.) It is the proportion of traffic traveling in the peak direction during a selected hour, usually expressed as a percentage. A road near the center of an urban area often has a D near 50% with traffic volumes equal for both directions. A rural arterial may exhibit a significantly higher imbalance because traffic is traveling toward an urban area in the morning and away from an urban area in the evening. In Florida, values for D range between 50% and 80%. Unless otherwise stated, D is the percentage of traffic traveling in the highest direction of travel during the 30 th highest hour of the year as measured at continuous monitoring sites. D factors are found in the 200 Highest Hours Report published by the Central Traffic Monitoring Handbook Page 8 of /30/07

9 IV Abbreviations and Definitions DAILY TRUCK VOLUME (DTV) Office. See the Project Traffic Forecasting Handbook for additional details. The most commonly used D factors are: D30 the proportion of traffic in the 30 th highest hour of the year traveling in the peak direction. It is used for design year capacity analysis. D100 the proportion of traffic in the 100 th highest hour of the year traveling in the peak direction. This is often used in calculating the level of service for a roadway. D200 - the proportion of traffic in the 200 th highest hour of the year traveling in the peak direction. NOTE: The definitions above relate to capacity analysis. Another D factor is used for pavement design. The pavement design D factor is the 24-hour loading factor. The value of the directional load distribution factor is 50% for two-way highways and 100% for one-way roads. The total volume of trucks on a highway segment in a day. (Also see TRUCK) DEBOUNCE A setting on traffic counters that compensates for the extra air pulses generated by a rubber hose bouncing on the pavement. DEFAULT VALUE A value assigned to a site by TRANSTAT when a required statistic has not been obtained. Refer to the Assignment Priorities chart in Chapter VIII. DESCENDING DIRECTION The direction of travel from the ending milepost toward the beginning milepost on a roadway section. Descending direction is South or West. (See ASCENDING DIRECTION and ROADWAY SECTION) DESIGN HOUR The 30 th highest traffic volume hour of the year. DESIGN HOUR FACTOR Proportion of 24-hour traffic volume occurring during the design hour for a given location or area. DESIGN YEAR The year for which the roadway is designed. Usually 20 years from the Opening Year, but may be any time within a range of years from the present (for restoration type projects) to 20 years in the future (for new construction type projects). The year for which the roadway is designed. DIRECTIONAL DISTRIBUTION (D) The percentage of total, two-way peak hour traffic that occurs in the peak direction. Traffic Monitoring Handbook Page 9 of /30/07

10 IV Abbreviations and Definitions EQUIVALENT SINGLE AXLE LOAD (ESAL) (Linked to Project Traffic Forecasting Handbook) A unit of measurement equating the amount of pavement consumption caused by an axle or group of axles, based on the loaded weight of the axle group, to the consumption caused by a single axle weighing 18,000 lbs (80 kn). FACTOR A number that represents a ratio of one number to another number. The factors used to adjust traffic volumes are K, D, T Design Hour Factor, Peak Hour Factor and Seasonal Factor. The Load Equivalency Factor adjusts pavement damage calculations. A proportion, usually expressed as a percentage. Factors that are described in detail in this Handbook are K, D, T, Axle Factor, and Seasonal Factor. See the FDOT Project Traffic Forecasting Handbook for information regarding the following traffic adjustment factors that are produced during the Annual Traffic Count Program: 1) Design Hour Factor 2) Peak Hour Factor 3) Load equivalency Factor 4) Peak Season Factor 5) Peak Season Conversion Factor 6) Peak Season Weekday Average Daily Traffic 7) Model Output Conversion Factor FEDERAL AID COUNTS AADTs reported to meet HPMS requirements for off-system roadways. (see HIGHWAY PERFORMANCE MONITORING SYSTEM) FEDERAL HIGHWAY ADMINISTRATION (FHWA) The Federal agency that oversees federal highways and Federal Aid transportation projects. (See HIGHWAY PERFORMANCE MONITORING SYSTEM) FHWA CLASSIFICATION SCHEME F FLORIDA INTRASTATE HIGHWAY SYSTEM (FIHS) A method of counting, identifying and classifying different types of vehicles into categories as shown in the table in Appendix B. At the present time, only Classes 1-13 are used in Florida. Classes 1-3 are motorcycles, automobiles, and light trucks; Classes 4-13 are Trucks and Buses (referred to as T or T24). Class 14 is not currently used. Class 15 is unclassifiable vehicles, which will be included in Class 2. (Also see CLASSIFICATION COUNT and TRUCK) A highway network adopted by the Legislature that delineates an interconnected statewide system of limited access facilities and controlled access facilities developed and managed by FDOT to meet certain criteria and standards in a 20-year time period. The system is part of the total State Highway System and is developed and managed by FDOT for high-speed and high-volume traffic movements. Traffic Monitoring Handbook Page 10 of /30/07

11 IV Abbreviations and Definitions FLORIDA STANDARD URBAN TRANSPORTATION MODEL STRUCTURE (FSUTMS) A computer model used to forecast urban traffic volumes. Generally most Metropolitan Planning Organizations (MPOs) in Florida have at least one FSUTMS model covering their regional network. In the densely populated areas of the state, more than one model exists. FREEWAY A multilane divided highway having a minimum of two lanes for exclusive use of traffic in each direction and full control of access and egress. FUNCTIONAL CLASSIFICATION (FUN CLASS) The assignment of roads into a system of categories according to the character of service they provide in relation to the total road network. A two-digit number represents each category. FUNCTIONAL CLASSIFICATION CATEGORY GEOGRAPHICAL INFORMATION SYSTEM (GIS) GLOBAL POSITIONING SYSTEM (GPS) RURAL: 01 Principal Arterial Interstate 02 Principal Arterial---Other 06 Minor Arterial 07 Major Collector 08 Minor Collector 09 Local URBAN: 11 Principal Arterial---Interstate 12 Principal Arterial---Other Freeways and Expressways 14 Principal Arterial---Other 15 Minor Arterial 16 Collector 17 Local The K, D, and T default values are partially based on the Functional Classification of roadways. Refer to Chapter VIII for assignment priorities. Two levels of Functional Classification defaults are utilized. STATEWIDE DEFAULTS are calculated from data obtained from TTMS s throughout the State. DISTRICTWIDE DEFAULTS are calculated from data obtained from TTMS s within each District. A mechanism for storing and utilizing data. GIS are being adopted by many transportation agencies to allow for easier sharing of data---which is vital to implementation of ITS. (see INTELLIGENT TRANSPORTATION SYSTEMS) (see Traffic Monitoring Guide Section 2, Chapter 5) A method of locating a point on the earth s surface by triangulating between satellites to determine latitude and longitude. It is also used to describe the equipment that is used to obtain the measurements. (See LATITUDE/LONGITUDE) Traffic Monitoring Handbook Page 11 of /30/07

12 IV Abbreviations and Definitions HIGHWAY PERFORMANCE MONITORING SYSTEM (HPMS) HEADER A line of data at the beginning of a data file that describes the data that follows. It usually contains such information as the site number, date, number of lanes, and type of data collected. Review the SURVEY PROCESSING SOFTWARE MANUAL for details. (Also see SITE IDENTIFICATION CODE) A data collection system that has been developed for reporting traffic data to the FHWA. The HPMS has evolved into a combination of a universal count program that includes all NHS roadways (on-system and off-system), all principal arterials (State roadways), and a statistical sample for the remaining highway systems (off-system); all of which must be counted at least once every three years. In Florida, the principal arterials are counted every year. Volume data for off-system roads is very important to the local governments because it is used to apportion Federal-Aid funds. IMAGE VIEWER A PC computer program that allows a user to view the videolog images. INDUCTIVE LOOP A sensor usually consisting of 3 or 4 turns of gauge wire embedded in a rectangular (often 6 x 6 ) pattern sawn into the pavement. The loop is connected to a detector that places an electrical charge through the loop wire, thus generating an inductive (magnetic) field. When a vehicle travels through the inductive field, it causes the field to change its inductance, and is then counted by the traffic counter. INTELLIGENT TRANSPORTATION SYSTEMS (ITS) A system that applies a broad range of diverse modern electronic and communications technologies to the business of moving people and goods. Most ITS applications involve the collection, analysis, and use of Traffic Data to improve safety, efficiency and reliability of travel. One of the major emphases of the FHWA is the implementation of national ITS. Traffic Data must be of good quality and must meet the diverse needs of users; and traffic monitoring efforts must be coordinated and shared between State and other roadway agencies. (see the Traffic Monitoring Guide Section 2, Chapter 5, Appendix 2-A) (see GEOGRAPHICAL INFORMATION SYSTEM) Traffic Monitoring Handbook Page 12 of /30/07

13 IV Abbreviations and Definitions INVENTORY A database that includes detailed information about each Traffic Monitoring Site. 1) The STATION INVENTORY DATABASE, located on the mainframe, describes all Traffic Monitoring Sites throughout the State---including active (current-year) and deactivated (historic) sites. It describes County Number, Station Number, Location Description, Ascending/Descending Direction, Number of Lanes, Count by Lane instructions (yes or no), Median (is a two-way left-turn lane to be counted---yes or no), Sensor Type, Survey Type, Survey Program, Axle Factor Category, and Volume Factor Category. It also describes the location of the site by Roadway ID and Milepost. If desired, the Districts can also record latitude and longitude coordinates. (See Chapter VII Station Inventory.) 2) The PTMS INVENTORY DATABASE describes active Traffic Monitoring Sites for each District. It is downloaded by SPS from the Station Inventory Database to the District PC, where it is used by SPS to process current-year short-term traffic surveys. It includes the same information that is in the Station Inventory, but it does not include Roadway ID, and milepost. (See Chapter VII) K FACTOR (K) A factor used for design and analysis of traffic flow on highways. Unless otherwise stated, it is the proportion of Annual Average Daily Traffic (AADT) occurring in the 30 th highest hour of the year. K factors can only be calculated at continuous count stations that have a full year of data. The K factors can be found in the 200 Highest Hours Report published by the Central Office. K30 the proportion of AADT occurring during the 30 th highest hour of the design year. Commonly know as the Design Hour Factor. The K30 factor is critical in project traffic forecasting. The K factor has three general characteristics: 1) K generally decreases as AADT increases. 2) K generally decreases as development density increases. 3) K generally is highest on recreational facilities, next highest on rural suburban, and lowest on urban. K100 the proportion of AADT occurring during the 100 th highest hour of the design year. Commonly known as the Planning Analysis Hour Factor. K200 the proportion of AADT occurring during the 200 th highest hour of the design year. Traffic Monitoring Handbook Page 13 of /30/07

14 IV Abbreviations and Definitions LATITUDE/LONGITUDE (LAT/LONG) LEVEL OF SERVICE (LOS) MINIMUM/MAXIMUM TABLE (MIN/MAX) MODEL OUTPUT CONVERSION FACTOR (MOCF) NATIONAL HIGHWAY SYSTEM (NHS) NON-INTRUSIVE SENSORS Angular distances measured in degrees that locate a point on the earth s surface. Latitude measures distance north or south from the equator. Longitude measures distance east or west up to 180 degrees in either direction from a meridian passing through Greenwich, England. (See GLOBAL POSITIONING SYSTEMS) A qualitative assessment of a roadway s operating conditions or the average driver s perception of the quality of traffic flow. A LOS is represented by one of the letters A through F, A for the freest flow and F for the least free flow. Planners and Engineers approximate these qualitative representations quantitatively with equations, now computer programmed. Quantitative criteria for the different LOS are provided in the Highway Capacity Manual (1985 Special Report 209) as published by the Transportation Research Board, National Research Council, Washington, D.C., and Rule Florida Administrative Code, Level of Service Standards. LOOP See INDUCTIVE LOOP. A term used to describe the ADT range of Variance Factors utilized by SPS to help the Districts verify the accuracy of raw count volumes. (See VARIANCE FACTOR) MODEL See TRAFFIC DEMAND MODEL The MOCF is used to convert the traffic volumes generated by a traffic demand model (PSWADT) to AADT. The MOCF is the average of the 13 weekly Seasonal Factors (SF) during the peak season. Public roads that have been designated by Congress or the Federal Highway Administration as nationally important. In Florida the NHS is mostly on the SHS, but some NHS (primarily connectors to defense installations or intermodal transportation facilities) are on the County Highway System or the City Street System. NHS roadways are eligible for Federal Funds. (See HIGHWAY PERFORMANCE MONITORING SYSTEM) Traffic sensing devices (infrared, microwave radar, acoustic, laser and video) that are not imbedded in the roadway. (Also see SENSORS) PEAK HOUR The hour during which the most vehicles travel across a point on the highway. Survey Processing Software evaluates hourly traffic flow every 15-minutes, determines the Peak Hour, and prints the Peak Hour information on the synopsis report. To meet current FDOT requirements, SPS is programmed to report the volume of traffic occurring at 1700 hours (from 5 to 6 PM). Traffic Monitoring Handbook Page 14 of /30/07

15 IV Abbreviations and Definitions PEAK HOUR FACTOR (PHF) PEAK HOUR-PEAK DIRECTION The hourly volume during the maximum traffic volume hour of the day divided by 4 times the peak 15-minute rate of flow within that hour; a measure of traffic demand fluctuation within the peak hour. This factor is calculated by the Survey Processing Software when the Districts process each short-term count. The direction of travel (during the 60-minute peak hour) that contains the highest percentage of travel. PEAK SEASON The 13 consecutive weeks of the year with the highest traffic volume. PEAK SEASON CONVERSION FACTOR (PSCF) A factor used to convert the average weekday daily traffic to the Peak Season Weekday Average Daily Traffic (PSWADT). PEAK SEASON WEEKDAY AVERAGE DAILY TRAFFIC (PSWADT) PEAK-TO-DAILY RATIO (p/d) PIEZOELECTRIC AXLE SENSOR (piezo) PORTABLE AUTOMATIC VEHICLE CLASSIFIER (PAVC) The average weekday traffic during the peak season. FSUTMS traffic assignment volume represents PSWADT projections for the roads represented in the model highway network. For Project Traffic Reports, the PSWADT should be converted to AADT using MOCF. The highest hourly volume of a day divided by the daily volume. K30 (9-10%) is approximately 25% greater than the Peak-to-Daily ratio (7-9%). (Also see K FACTOR, PEAK HOUR, and PEAK HOUR FACTOR) A sensor consisting of a length of piezoelectric material encased within some type of housing. The sensor is installed across a roadway and used to detect axles. Whenever a vehicle s axles run over the sensor, the pressure on the piezoelectric material is converted into an electronic signal that can be detected by a traffic counter. A portable traffic counting device that is capable of classifying vehicles into the 13 FHWA Scheme F types. PORTABLE TRAFFIC MONITORING SITE (PTMS) A traffic monitoring site that has loops and/or axle sensors in the roadway with leads running back into a cabinet located on the shoulder. When a traffic count is desired, a portable counter is connected to the sensor leads and placed in the cabinet. After the count has been collected, the counter is removed and placed at another count site. The site isn t portable, just the counter. PROCESSED DATA A traffic survey that has been evaluated to make sure it contains all the required information, in the desired format. Short-term traffic counts may be processed by utilizing SPS. Counts must pass processing requirements before being analyzed for Acceptability. (See Chapter VII) Traffic Monitoring Handbook Page 15 of /30/07

16 IV Abbreviations and Definitions PTMS INVENTORY DATABASE See INVENTORY RAMP A turning roadway that connects two or more legs at an interchange, the geometry of which usually involves some curvature and a grade. Each ramp is usually a one-way roadway. RAW DATA Traffic data that has been downloaded from the counter, but has not been processed. This term is also used to describe processed counts that have not been adjusted by Axle or Seasonal Factors. (See PROCESSED DATA) RECORD SUMMARY REPORT (.RSR) ROADWAY CHARACTERISTICS INVENTORY (RCI) A multi-page, very detailed report of a short-term count. It contains County, station number, start date, type of survey; traffic counts in 15-minute increments by direction, lane, and classification category; totals by lane and classification category in 15-minute increments, hourly, and 24-hour increments; Truck Percentage by classification category; Peak Hour, Peak Hour Volume, Peak/Daily Factor and Peak Hour Factor; and Truck Volume. This report can be produced by the Survey Processing Software when the District processes the count. A database maintained by Transportation Statistics Office which contains roadway and traffic characteristics data for the State Highway System, including current year traffic count information such as AADT and the traffic adjustment factors, K 30, D 30, and T. These details are organized into categories and identified by Feature numbers. Features that are used to help with our Annual Traffic Count Program analyses are: 114 Local Name of Facility 121 Functional Classification 124 Urban Classification (Municipal/urban Limits) 251 Intersecting Streets (Milepost of) 326 Traffic Monitoring Sites (Count Station number and type) 331 Traffic Flow Breaks (Begin and End milepoint, AADT, date, type of count, K, D and T factor) ROADWAY ID NUMBER An identification number that is assigned to a piece of highway that is administered by the Florida Department of Transportation. (See ROADWAY SECTION) ROADWAY SECTION A roadway section or subsection is a state-owned or off-system roadway for which we collect information and maintain databases. It is identified by an eight digit code. The first 2 digits tell you what county it is in. The next 6 digits identify the roadway. Each roadway section is defined by a beginning and ending milepost in the Roadway Characteristics Inventory. Traffic Monitoring Handbook Page 16 of /30/07

17 IV Abbreviations and Definitions ROAD TUBE A rubber hose that is placed across a road and used to detect a vehicle s axles. SECTION see ROADWAY SECTION SECTION BREAK A section (traffic) break represents a segment of highway with uniform traffic volume and vehicle mix. AADT and the average K30, D30, and T must be provided for every section break of the State Highway System. (Also see BREAK POINT and ROADWAY SECTION) SEASONAL ADJUSTMENT FACTOR (SF) See SEASONAL FACTOR. SEASONAL FACTOR (SF) Parameters used to adjust short-duration counts which consider travel behavior fluctuations by day of the week and month of the year. The Seasonal Factor used in Florida is determined by interpolation between the two consecutive monthly factors to create one SF for each week of the year. Refer to Chapter VIII. for more information. SHORT-TERM COUNT PROGRAM SENSORS Devices that detect the presence of traffic and transmit survey data to counters. (also see INDUCTIVE LOOP, NON-INTRUSIVE SENSORS, PIEZOELECTRIC AXLE SENSOR, and ROAD TUBE) The Annual Traffic Count Program conducted by the Districts to provide roadway segment-specific traffic count information. SHORT-TERM MONITORING SITE SITE IDENTIFICATION CODE STATE HIGHWAY SYSTEM (SHS) STATE ROAD NUMBERING SYSTEM Locations where portable traffic counters are temporarily placed to record the distribution and variation of traffic flow. (Also see TRAFFIC MONITORING SITE) A 10-digit number located in the header of traffic counts collected in the.prn format. It is usually programmed into the counter by the field technician when preparing to collect a traffic survey. The 10-digit code is required by the Survey Processing Software to identify the following details about the count: County, Station Number, direction counted, number of lanes or channels counted, and the order in which each lane or channel is counted. (Also see HEADER) Roads owned and maintained by the State of Florida. Florida roads are numbered as Interstates, US Routes, State Roads or County Roads. Interstates and US Routes are also assigned State Road Numbers. Odd numbers are assigned to north/south routes with the low number beginning on the east coast and progressing higher toward the west coast. Even numbers are assigned to the east/west routes with the low number beginning at the north end of the state and progressing higher toward the south end of the state. Traffic Monitoring Handbook Page 17 of /30/07

18 IV Abbreviations and Definitions STATION The 6-digit number used to identify and store traffic counts. It consists of a 2-digit county number followed by a 4-digit site sequence number. The 6-digit composite number is unique statewide. Also see TRAFFIC MONITORING STATION. STATION INVENTORY A database that contains essential information about a traffic monitoring site, such as its location, current status, type of data collected, number of lanes, and factor categories. The Station Inventory is located on the Mainframe in the TRAFFIC CHARACTERISTICS INVENTORY Database STRAIGHT-LINE DIAGRAM (SLD) SURVEY PROCESSING SOFTWARE (SPS) see SPS MANUAL SYNOPSIS REPORT (.SYN) A linear graphical representation of select physical and descriptive characteristics along the travelway of a roadway. These characteristics are obtained from the RCI database. (See ROADWAY CHARACTERISTICS INVENTORY) - A software package developed to provide FDOT District Offices with a program that can transfer data from a variety of highway traffic counters to PCs, perform standards editing, and then transfer summarized classification and count data from their PC s to the FDOT mainframe. A one-page summary of each 24-hour short-term traffic count. This report is produced by the Survey Processing Software when the District processes the count. All synopsis reports format the data to begin and end at midnight to make it easier to see the daily traffic flow. It contains the county number, count site number, location description, date of count, start-time of count, directional count in 15-minute increments, hourly totals, two-way totals, daily total, Truck Percentage, and Peak Information (A.M., P.M., and Daily Peak Hour and Peak Volume by direction and combined directions). T FACTOR (T24) Truck Factor; the percentage of truck traffic in the AADT. (see TRUCK) TELEMETERED TRAFFIC MONITORING SITE (TTMS) A continuous traffic monitoring site that transmits traffic data to the TRANSTAT Office via telephone or wireless communications. (See CONTINUOUS MONITORING SITE) TRAFFIC BREAK A segment of highway that is reasonably homogenous with respect to traffic volume, vehicle classification, and general physical characteristics (e.g., number of through lanes). See SECTION BREAK TRAFFIC CHARACTERISTICS INVENTORY (TCI) A database maintained by Transportation Statistics Office which contains both historical and current year traffic count information including AADT and the traffic adjustment factors, K 30, D 30 and T. Refer to Chapter VII for more information. Traffic Monitoring Handbook Page 18 of /30/07

19 IV Abbreviations and Definitions TRAFFIC DEMAND MODEL TRAFFIC MONITORING STATION (TMS) TRAFFIC SURVEY see COUNT In broad terms, a computerized mathematical description of a transportation system that uses traffic volumes, land use, roadway type, population data, as well as socioeconomic, roadway and travel behavior to predict future traffic volumes. It produces a travel simulation that is used to analyze and plan for future transportation needs. The model used in Florida is the Florida Standard Urban Transportation Model Structure (FSUTMS). See the Project Traffic Forecasting Handbook for additional details. - A specific location on a roadway where traffic count surveys are conducted for the Annual Traffic Count Program. Each survey location is identified by a six-digit number and recorded in the Station Inventory Database on the mainframe. The first two numbers represent the County; the next four digits represent the count site on the roadway. (see SHORT TERM MONITORING SITE, TELEMETERED TRAFFIC MONITORING SITE, and TRAFFIC CHARACTERISTICS INVENTORY) TRANSPORTATION STATISTICS OFFICE (TRANSTAT or TSO) The FDOT Central Office in Tallahassee that monitors and reports statistical traffic information for the State Highway System. VARIANCE FACTORS (MIN/MAX Factor) TREND A general tendency based on historical data. A traffic trend allows for an estimation of future volume from historical traffic counts. TRUCK Any heavy vehicle described in FHWA Scheme F (see Appendix B), Classes 4-13; i.e., buses and trucks with six or more tires. Class 14 is available for state definition of a special truck configuration not recognized by Scheme F, but is not used in Florida. (see T FACTOR and FHWA CLASSIFICATION SCHEME F) The minimum and maximum allowable volumes for each count site. There are two sets of variance factors for each count station for each month of the year. One set provides the limits for axle count surveys, and the other set provides the limits for vehicle count surveys. They are calculated by TranStat at the close of each Annual Count Year by dividing the AADT by the monthly seasonal and axle adjustment factors. The variance factors are used by the Survey Processing Software to determine whether or not a traffic volume is acceptable. If the count falls outside this acceptable range, SPS creates an error record and it is up to the system operator to make the final decision as to whether the count is accepted or rejected. VIDEOLOG A visual gateway into the Department s digital assets that allows you to view photographs taken every 52 along every segment of roadway in the State Road System. Go to the Infonet Home Page, Traffic Monitoring Handbook Page 19 of /30/07

20 IV Abbreviations and Definitions select Planning from the pull-down menu for Department Intranet Sites, select Videolog Images from the Site Index on the Planning Page and click GO. VOLUME FACTOR See SEASONAL FACTOR WEIGH-IN-MOTION (WIM) The process of estimating a moving vehicle's static gross weight and the portion of the weight that is carried by each wheel, axle, or axle group or combination thereof, by measurement and analysis of dynamic forces applied by its tires to a measuring device. WIM sites are installed and maintained by TRANSTAT. Traffic Monitoring Handbook Page 20 of /30/07

21 V Short-Term Program V. SHORT-TERM PROGRAM SHORT-TERM MONITORING SITES Short-Term Monitoring Sites provide roadway segment-specific traffic count information on a cyclical basis. Short-Term counts are sometimes called seasonal, portable or coverage counts. Video 2 Site Selection Road tubes Traffic counters frequently use rubber road tubes to sense and record the number of axles at a count location. When a vehicle s axle crosses the road tube, the pulse of air that is created is recorded and processed by the traffic counter. The road tube is extended across the desired lanes or directions that need to be counted, and depending on the type of count needed, one of several different road tube configurations may be placed in the roadway. Data collection personnel are responsible for all road tube tests and inspections. At least once per month, replace each road tube---or blow clear and test for leaks by the application of air pressure. Visually inspect each road tube for adequate condition prior to each use. Traffic Monitoring Handbook Page 21 of /30/07

22 V Short-Term Program Site selection for road tube placement (Short-Term Monitoring Sites) When determining locations for road tube sites, it is important to select a location that will give the most accurate and useful data possible. When setting road tubes, you should consider the following factors: 1) Avoid curves, if possible. 2) Don t set at driveways. 3) Don t set by schools. 4) Avoid setting close to intersections, if possible counters require vehicles of constant speed above 30mph to work properly. 5) Road tube spacing is dependent upon average vehicle speed and equipment requirements. 16 feet is recommended for interstates; 10 feet is recommended for 55 mph roads; and 6 feet is recommended for low speed urban roads, ramps, and curves 6) Adjust the debounce setting. 7) For the best vehicle classification, both road tubes must be of the same type and condition, and within 1 inch in length. 8) Hold the road tube to your ear to feel for an air pulse if no pulse is felt, get another hose. 9) Ensure the counter is secured in a dry location possibly hang it above the ground. 10) Tape down hoses to minimize hose bounce. It is recommended to use a minimum of 5 pieces of tape per lane. 11) If nothing is available to which a counter can be secured, drive a metal delineator post (with visible marking) into the ground, and secure the counter to it. 12) For locations that are revisited, consider permanently installing nails (driven close to the road surface) and marking the location for future use. 13) Do not set when the pavement is wet. 14) Hoses must be set perpendicular to the road, and the same amount of tension should be applied to each hose. 15) Safety is always a factor when driving nails and placing hoses. Traffic Monitoring Handbook Page 22 of /30/07

23 V Short-Term Program Inductive loop/ piezoelectric axle sensor sites Peek 241-A There are a number of locations throughout the state where permanent loops and piezo sensors have been installed in the pavement. These sensors may be connected to portable counters and used to collect short term vehicle counts, speed or class surveys, depending upon the sensor configuration. A single loop is required to collect traffic volume data. Two loops are required to collect speed data. Two loops and a piezoelectric sensor in each lane are required to collect classification data. ADR 3000 Diamond Site location determination When determining locations for inductive loop/piezoelectric axle sensor sites, it is important to select a location that will give the most accurate data possible. Some of the factors that should be considered or reviewed when selecting a site location are as follows: 1) Avoid driveways and curves 2) Avoid acceleration/deceleration areas 3) Away from intersections. 4) Free flow traffic 5) Locate the cabinet in an area safe from traffic, where the technician can see both directions of traffic. 6) Location that is easy to access from roadway, with off-road parking. 7) Avoid high pedestrian traffic areas. 8) Locate the cabinet such that the recorder display and the traffic can be viewed simultaneously. Traffic Monitoring Handbook Page 23 of /30/07

24 V Short-Term Program Sources for review Recommendation for installing new inductive loop/piezoelectric sites Tracking of installation Installation/Inspection Sources for review when selecting site locations are: 1) Review of Design plans at 30% stage, or earlier (Construction, Reconstruction, Resurfacing), so that, if desired, loops and piezo sensors can be installed in the pavement for future use as a PTMS. 2) Review video logs for possible traffic monitoring sites. 3) Perform field inspection There are certain criteria that should be looked at when determining and recommending the installation of a new inductive loop/piezoelectric sites. The following guidelines should be used: 1) Is the site really needed? 2) Recommended to be added by time of 30% Design plans (Construction, Reconstruction, Resurfacing) 3) If the road geometry precludes use of road tubes 4) Safety concerns in the area to be counted 5) High speed locations (Interstate) 6) Accident history at location 7) Areas of high traffic Each District will develop a tracking method to assure sensors are installed according to plans and working properly after installation. 1) Once it is determined that a site will be installed, it is important to get project status reports as soon as possible from the construction department. 2) If possible, attend the Pre-construction meeting to advise all parties of your interests in the site. 3) It is also helpful to get a contact phone number as soon as possible. This will make the communication between the responsible parties more efficient. 4) Begin close follow up once the installation has begun. 1) All sites must be inspected to determine that they have been built according to the plans and are in proper working condition before payment is approved. The following list of references will be used when working with the installation and inspection of inductive loop/piezoelectric axle sensor sites: Plan Notes Roadway and Traffic Design Standards Standard Index Loop installation details (Appendix C) Standard Index Cabinet installation details (Appendix D) Standard Index Traffic monitoring site details (Appendix E) Traffic Monitoring Handbook Page 24 of /30/07

25 V Short-Term Program Equipment The following equipment is recommended when working on, troubleshooting, or inspecting a permanent site: VOM (Voltage-Ohm-Milliamp) Meter Laptop Computer Earth Ground Tester Loop Wire Insulation Tester Tool kit with all applicable tools (Pliers, screwdrivers, etc.) Oscilloscope Traffic Counter Gloves Shovel Broom Lubricant Insect repellant Wasp spray Insecticide Axe Pruners or shears VOM Meter Oscilloscope Phone Maintenance Non-Intrusive Technologies Earth Tester Frequency Tester Laptop Computer Counts will be taken by other methods while the site is under repair. Non-intrusive technologies are devices that can collect certain traffic data without having equipment used in the roadway. Most of these devices can collect volume, speed, and length based classification counts. These counters do not collect axle based classification counts. The following is a list of currently available technologies that could be used: Infrared Microwave radar Acoustic Laser Video Traffic Monitoring Handbook Page 25 of /30/07

26 V Short-Term Program TRAFFIC COUNTERS AND EQUIPMENT Video 3 Equipment Acceptable Traffic Counters Peek 241A/ADR1000 The majority of traffic counting locations have periods of congested traffic flow during which the axles of two or more vehicles are within 40 feet of each other. The counter shall have the ability to correctly classify vehicles during these tailgating conditions. Each traffic counter placed in the field should have a legible tag showing the name and telephone number of the owner. If the count is being collected by a contractor for FDOT, the name and telephone number of the FDOT contract administrator should also be written on the tag. Acceptable traffic counters must have the following capabilities: 1) Record traffic count data (axle, vehicle, speed and/or classification) in user selected intervals 2) Accept the user inputted 10 digit ID code required by the Survey Processing Software 3) Provide a data output file that can be read into the SPS. Diamond Peek ADR3000 Traffic Monitoring Handbook Page 26 of /30/07

27 V Short-Term Program MetroCount Jamar Certification of traffic monitoring equipment Traffic Technician Equipment All traffic counters used by the Department or their consultants for general data collection activities must be certified for accuracy at least once per year. See Traffic Monitoring Equipment Certification Form (Appendix A). These certifications must be turned in to the Central Office no later than January 31. Each counter shall be tested for accuracy with a specialized traffic counter tester. All sensor inputs (air switches, contact closure boards, loop boards and/or piezo boards) will be tested. A minimum test will consist of a 15-minute survey. The counter shall have a minimum of 97% accuracy. All District and consultant vehicles shall be equipped with the following equipment: 1) Orange Safety vests (worn by technician during all field operations) 2) Four-way flashing lights and a minimum of two yellow strobes mounted on a light bar 3) Appropriate tools and supplies (eg., spray paint, asphalt tape, nails, hammer, etc.) 4) Appropriate manuals for counters 5) Fire extinguisher 6) First aid kit 7) Two-way radio or cellular phone 8) Orange cone 9) Traffic counters 10) Security chains and locks Traffic Monitoring Handbook Page 27 of /30/07

28 V Short-Term Program SAFETY PROCEDURES FOR TRAFFIC COUNT PERSONNEL Video 4 Safety Procedures All traffic count personnel must be provided a minimum of two weeks of training by accompanying an experienced field technician who is collecting traffic data. All personnel must be provided training in first aid techniques and be familiar with the following safety procedures before they are allowed in the field. All vehicles used for traffic data collection will be equipped with the minimum equipment specified above. All traffic count personnel shall adhere to the following procedures: 1) Seat belts shall be worn during operation of vehicles. 2) Orange safety vests and UL approved safety glasses or safety prescription glasses shall be worn during field operations. 3) Reflective safety vests shall be worn during low visibility situations. 4) Vehicle lights shall be used in the following manner: a) Turn signal and yellow roof mounted strobe lights shall be activated as the traffic count vehicle approaches the work site, usually five hundred to one thousand feet ( ) in advance of the site. b) Four-way flashers shall be activated at the work site and the flashers and strobe lights shall remain activated until the proper turn signal is activated to leave the work site. c) Strobe lights shall be turned off after the vehicle safely reenters traffic flow. 5) All traffic count personnel shall conform to OSHA RULES & REGULATIONS. 6) Vehicles shall be parked where there is adequate space to park the vehicle safely without blocking sidewalks and driveways. The vehicle should be parked a minimum of four (4) feet from the edge of the pavement. 7) All traffic count personnel shall exercise extreme caution when entering the roadway to set or retrieve traffic sensors. 8) Under no circumstances shall traffic sensors be placed in the roadway when it is raining or foggy. 9) All traffic count personnel have the right to request that their supervisor assign additional help to assist them if they deem there is a need for a two-person crew to set equipment safely. 10) Only state vehicles are authorized to cross the Interstate medians. All other vehicles are subject to moving violations. 11) Night work should be done only when traffic flow dictates it to be necessary, and then only with two or more technicians. One person should spot while the other is working near the pavement. At least one set of eyes should always be on traffic when someone is working in the traveled way. Reflective vests must be worn at all times when working at night. Traffic Monitoring Handbook Page 28 of /30/07

29 V Short-Term Program SITE SELECTION Traffic (Section) Break Segments Video 5 Traffic Break Example Each Roadway Section and Subsection is defined by a beginning and an ending milepost in the Roadway Characteristics Inventory (RCI) database. Sections and Subsections are divided into smaller continuous segments that have similar traffic volumes and truck traffic; these smaller segments are called Section Breaks, Traffic Breaks, or just Breaks. AADT and the K30, D30 and T must be provided for every section break of the State Highway System. Traffic Breaks are defined in the Traffic Characteristics Inventory (TCI) database. Breaks are defined by beginning and ending mileposts called break points. Break points are always located at the beginning and ending of each Roadway Section and Subsection, at the beginning and ending of exceptions, and where State and Federal roads intersect the Section. Additional break points are located where there are significant changes in traffic characteristics; these changes usually occur at intersections. The characteristics of the highway can also govern break points. Each year, through the exercise of engineering judgment on the part of the District traffic personnel, Section Breaks are reevaluated. Break points are added, deleted or moved to reflect changes in inventory and field conditions. Listed below are some considerations for determining the location of break points: 1) Where changes in total traffic volume exceed 20% (under 5,000 AADT) to 10% (over 25,000 AADT) 2) Where changes in total truck volume exceed 250 vehicles per day. 3) Traffic changes often occur where major County roads intersect State highways. Breaks are usually placed at these intersections even if there is no significant change in traffic volume or vehicle mix, just to prove there is no significant change. 4) The location of City Limits and speed limits. 5) Roadway geometry (for example, a change in the number of lanes may indicate a change in traffic characteristics). 6) Major commercial or residential development (such as shopping centers or subdivisions). 7) Truck stops and industrial areas may indicate a change in truck traffic. Traffic Monitoring Handbook Page 29 of /30/07

30 V Short-Term Program Station Locations Video 6 Site Selection Basics It is the responsibility of the Districts to determine the location of traffic monitoring sites. The exact location and count type are often determined by the physical geometry of the highway (see Chapter V). Each time a count is made, the technician will re-evaluate the site to determine if field conditions are still suitable for obtaining an accurate count. Some of the factors that should be considered when selecting site locations are the presence of: Curves Crests Valleys Driveways Intersections Schools Number of lanes Medians Shoulders Turn lanes A traffic count station is usually located within each traffic break segment. It is important to note that connecting roadway sections (i.e. adjacent urban/rural sections, and segments that adjoin one another at county lines), can utilize count data from a station located on either side of the traffic break as long as the same roadway and traffic characteristics exist. This helps reduce the number traffic counts that must be collected, processed and stored. Routine traffic count surveys should be limited to the mainline sections only. Ramps are only counted when there is a specific reason to do so. Traffic Monitoring Handbook Page 30 of /30/07

31 V Short-Term Program TYPE OF COUNT, COLLECTION PERIODS AND DURATIONS Volume counts Classification Counts T 24 24T 24T+B = Heavy Trucks Large Trucks CLASS. GROUP Any 7 or more axle FHWA 14 Not Used Scheme F There are two different types of volume counts that can be collected: Axle volume counts are usually obtained when a single road tube is set across a road. The counter connected to this road tube divides the number of hits on the tube by 2. This type of count data requires an axle adjustment to generate a vehicle count. Vehicle volume counts are obtained from counters that use sensors that detect an entire vehicle, not simply its axles. The most commonly used type of these sensors are inductive loops. Classification counts can be collected and classified two different ways: Axle classification Axle classification consists of collecting traffic data with counters that detect axles and measure the distances between axles on each vehicle. The vehicle is then classified according to the criteria contained in FHWA Classification Scheme F (see Appendix B). Classification data are usually collected using two axle sensors or a combination of presence (loops) and piezoelectric axle sensors. Length classification This type of count is derived by detecting the presence and length of a vehicle and classifying it into preset length groupings. To determine length classifications, several different types of presence detectors (microwave, magnetic, radar, loop) can be used to record the vehicles length. Presently length classifications are not used by Florida DOT. Classification surveys required at congested locations might require additional presence detection sensors or advanced detection technology. Counters utilizing road tube and loop/piezo sensors often will not classify well at locations with stop-and-go traffic. Traffic Monitoring Handbook Page 31 of /30/07

32 V Short-Term Program Performing Counts While installing and performing traffic counts, there are several procedures that should be adhered to with regards to placement of the traffic counter and sensors: 1) Traffic counters should be placed at locations specified by the District Traffic Count Manager, or as listed on the Survey Processing Software Inventory Database. 2) Ascending and descending directions should be counted at the same milepost. In congested areas with many intersections and driveways, this may not be possible. 3) All count interval times must be consecutive throughout the duration of the count. 4) Both ascending and descending directions must be counted for identical dates and times. 5) All count locations should have field equipment (traffic counter and sensors) verification checks done prior to leaving site to assure accuracy. 6) Collect GPS coordinates (dependant on District) 7) Each counter must have the descriptive 10-digit identification code entered by the technician as the counter is set so that the Survey Processing Software will know how to handle the resulting data file. Refer to the SPS manual for examples of the 10-digit identification code. 8) Avoid construction affected locations. Don t place counters and hoses too close to an intersection Mid-block locations where traffic moves freely over the hoses Traffic Monitoring Handbook Page 32 of /30/07

33 V Short-Term Program Acceptable times Duration of Counts Recount Conditions Field observed recount conditions Office determined recount conditions Obtaining data that is most useful for historical trend reporting and forecasting requires that the collection period be taken during a time in which traffic would be representative of the traffic patterns on the typical weekday. There are several guidelines that should be followed to help minimize collecting atypical data: 1) Counts should occur between Monday 6:00a.m. and Friday 2:00p.m. 2) Avoid collecting data prior to, during, or right after, holidays or special events. The duration of the volume or classification count is dependant on the requirements of the District as well as the project. For the Annual Count Programs throughout the Districts, count locations are identified as either by the functional classification of the road on which they are located as either Rural or Urban. Because there is more day-today variation in the traffic flow in rural areas, a longer count duration is required to minimize this variation. The minimum requirements for Rural and Urban counts are as follows: Rural minimum of 48-hours of continuous data in 15-minute intervals Urban minimum of 24-hours of continuous data in 15-minute intervals Some traffic counts will have to be re-taken. When recount conditions are noted in the field, the site will be recounted before being submitted to the District Traffic Count Manager. Once a traffic counter has been set, the following guidelines should be followed to ensure that the collected data is accurate, and will help determine if there is a reason to re-take the count. In general, a recount condition will occur when: 1) One or more of the machines at a designated count station mechanically fails to properly complete the count period. 2) One or more tubes were damaged or come loose. 3) An incomplete or inaccurate classification or volume count occurs for any portion of the count period. 4) The count was made in the wrong location. 5) The count was affected by an abnormal occurrence, such as a construction detour, long delay, special event, emergency incident, or adverse weather conditions. A recount is necessary when the SPS check detects errors and subsequent tabulation and review of count results verify the need for a recount. This condition can only be determined after District personnel have analyzed the submitted count information. (see Chapter VII Processing of Short-Term Count Data) Traffic Monitoring Handbook Page 33 of /30/07

34 VI. Continuous Monitoring Program VI. CONTINUOUS MONITORING PROGRAM The Continuous Monitoring Program is operated by the Central Office. Data from these continuous monitoring sites are collected daily and are used to produce AADT and K, D, and T factors. Continuous count data is also used to develop seasonal adjustment factors, and the continuous class data is used to develop axle adjustment factors. FDOT has more than 300 Continuous Monitoring Sites located throughout the State that are used to collect vehicle volume, speed, classification and truck weight data. VOLUME MONITORING SITES SPEED MONITORING SITES CLASSIFICATION MONITORING SITES All of Florida s continuous traffic monitoring sites are capable of collecting traffic volume data. The data is collected for each lane, and usually for one-hour intervals, although the intervals can be varied as needed (any period that divides evenly into 60 minutes). The most common type of sensor used to collect volume data at a continuous traffic monitoring site is a single inductive loop. Several volume-monitoring-only sites have been built using microwave radar sensors, generally in locations where the highway geometry or traffic volume make it difficult to install loops. Other types of continuous traffic monitoring sites are often set to collect volume-only data when some of their sensors have failed and are awaiting replacement. Most of the continuous traffic monitoring sites are capable of collecting vehicle speed data. Since 1995 all such sites have been routinely programmed to collect this data in binned files. Florida currently bins the speed data into 15 categories: <=20mph, 21-25mph, 26-30mph, 31-35mph, 36-40mph, 41-45mph, 46-50mph, 51-55mph, 56-60mph, 61-65mph, 66-70mph, 71-75mph, 76-80mph, 81-85mph, and >=86mph. The speed data is collected by lane for each recording interval. Only in rare cases are the speed data collected by class of vehicles, because these types of data files grow extremely large. The majority of Florida s continuous traffic monitoring sites are built to collect vehicle classification and speed data. Florida collects axle class data according the FHWA Scheme F standard. The most typical sensor configuration used to collect vehicle class data consists of a loop-piezo-loop array, although there are a couple of piezo-loop-piezo sites, and even an experimental Idris loop classification site. Traffic Monitoring Handbook Page 34 of /30/07

35 VI. Continuous Monitoring Program WEIGH-IN-MOTION SITES Types of weigh-inmotion sensors Bending Plates Piezoelectric Sensors Quartz piezoelectric sensors Florida has been collecting truck weight data through the use of weigh-in-motion equipment since Beginning in 1988, permanent weight sensors and electronics have been installed in selected locations, and the systems are monitored continuously. The weigh-in-motion equipment collects the speed, vehicle classification, axle weights, and axle spacings of every vehicle that passes over the sensors. The vehicle class and speed data are binned similarly to the continuous speed and classification sites. The vehicle weight and axle spacing data are only saved for vehicle classes 4 and higher, in order to conserve memory in the counters. These are the classes of vehicles that exert the most force on the pavement structures, and are used for pavement design and analysis. Typically used in one of two configurations, either a pair of bending plates placed adjacent to each other (one in each wheelpath) located between a pair of inductive loops, or a single bending plate placed in one wheelpath located between a pair of inductive loops. The two plates provide a more accurate weight than a single plate, but at twice the expense. The dual bending plate systems have been installed in high-speed, high-volume highways, in concrete pavements, so as to minimize the chance they may break out of the road. Single bending plate sensors have been placed in several flexible pavements that experience low to moderate truck volumes. Piezoelectric axle sensors that generate a uniform signal along their length are designated as Class II sensors. These Class II piezo sensors are used in several different configurations to weigh vehicles. The most commonly used configurations in Florida are: leading right piezo, leading loop, leading left piezo, trailing right piezo, trailing loop, trailing left piezo; and leading piezo, loop, trailing piezo. The piezo sensors have been placed in flexible pavements, where their design allows them to be mounted flush with the pavement s surface. Florida has installed quartz piezoelectric axle sensors at a couple of locations. These sensors are reputed to be unaffected by temperature, and to provide weight data comparable to bending plate sensors (at about the same cost as bending plate sensors). However, since the quartz sensors are about the same size as the regular piezoelectric sensors, they can be installed in flexible pavements with little danger to the motoring public. The typical quartz sensor configuration is a leading sensor in the right wheelpath, a loop, and a trailing sensor in the left wheelpath. Traffic Monitoring Handbook Page 35 of /30/07

36 VII. Weekly Data Processing VII. WEEKLY DATA PROCESSING PROCESSING OF SHORT-TERM COUNT DATA Survey Processing Software (SPS) To maximize the efficiency and accuracy of traffic data, the Districts and Central Office must conduct a comprehensive analysis process that involves more than just obtaining and processing raw counts. They must analyze the counts for acceptability, evaluate and monitor conditions that affect traffic data, and maintain a Traffic Count Program that will obtain an accurate picture of evolving traffic characteristics. All traffic surveys performed for the annual program should be processed and uploaded to the FDOT mainframe using the Survey Processing Software. SPS was developed to provide the FDOT Districts with a software package that could transfer raw data from a variety of traffic counters to a PC, perform the required edits on the raw data, and then upload summarized classification and count data statistics from the District PC to the FDOT mainframe. SPS is a custom application written within Microsoft Access. Refer to the SPS User Manual for operating instructions. Traffic Monitoring Handbook Page 36 of /30/07

37 VII. Weekly Data Processing The four main functions of SPS are: 1) Convert Raw Data 2) Load SPS Database Video 7 Load SPS 3) Edit SPS Database Video 8 Edit SPS This function was designed to download the files contained in the traffic counters to the District or Consultant PC. It was written so that FDOT need not purchase multiple copies of each counter manufacturer s proprietary software and spend the time learning how to use each. With SPS, the same steps are performed by the technician to download the counter data, regardless of brand--the software handles all the special vendor commands. Once the traffic data files have been extracted from the counters, they must be loaded into the SPS Access database before they can be further analyzed. This routine can read the files created by the previous step, and can also read the proprietary file formats created by several of the vendor software packages. All files transferred to the Districts by the Consultants must be in an *.txt or *.prn file format. These files can be transferred by disk, attachments, or through the FTP site. When SPS loads the data into its database, it organizes the data into 24-hour blocks starting with the first data interval. It also organizes the data by station and by date. If less than 24-hours of data is available, further processing cannot be undertaken. The edits performed by SPS alert the Districts to possible problems with the quality and accuracy of the counts by comparing each traffic survey to information stored in two tables---the Station Inventory and the Variance Factors tables. If there are discrepancies, SPS creates error messages for analysis by District personnel. The operator can verify the accuracy of the count, make corrections to the input data files, or update the Station Inventory. (See SPS EDITS PERFORMED and PROBLEM RESOLUTION) Toward the end of this step, SPS asks the user if it should create Record Summary and Synopsis reports. The Record Summary Report is primarily useful in examining classification data by hour of the day and by lane. The Synopsis Report displays a single day of volume information on one sheet of paper, shows the calculated morning and afternoon peak hour data, and, for classification surveys, shows the Truck Percentage (T%). Even though the actual count may start at any time of day, SPS reorganizes the data into a uniform format running from midnight to midnight. This format makes it easy for the user to see how traffic flows through the day. A final set of mental edits should be performed on the data before it is transferred to the mainframe. These edits are not performed by SPS, but by the user: are the types of vehicles and the volumes reasonable for the location where the count was collected? (See ANALYZING THE DATA) Traffic Monitoring Handbook Page 37 of /30/07

38 VII. Weekly Data Processing 4) Upload Data to Mainframe Video 9 Upload Data The final step in processing the traffic data through the Survey Processing Software is creating the summary records that are transferred to the mainframe. SPS creates for each station and date a single annual summary record, and a daily summary record for each direction of traffic data. Additionally, SPS adds the seasonal factor category from the Station Inventory to the volume summary record. If the volume data is from an axle counter, SPS also adds the axle factor category. The summary records created by SPS to upload to the mainframe database are: ANS -- The annual summary record, which contains the county, site, year, date, peak hour time, peak hour volume, peak hour truck volume, peak/daily ratio, and peak hour factor. CNT -- The daily volume record, which contains the county, site, year, direction, date, survey type, survey program, total volume, seasonal factor category, and axle factor category. CLS -- The daily vehicle classification record, which contains the site, year, direction, date, survey type, survey program, class 01 through class 15 volumes, total volume, and truck volume. The summary records described above are written by SPS into a file named NCTRAFF.FDF that is transferred to the mainframe. A message will appear in the Status bar to tell the user when the transfer is complete. Upon successful transfer, SPS then automatically launches a batch job that tries to load this summary data into the mainframe TCI database. The load program will then notify the user via about the status of the upload. The lists those records successfully loaded, and will create an error file for unsuccessfully loaded records. If an error file was created during the TCI upload, the user can log into TCI, click on the District Tab, make corrections to the ANS, CNT or CLS records, and re-submit the load job. Or the user may elect to make corrections to the appropriate data files on the PC, and rerun that station s data through the entire SPS process. Traffic Monitoring Handbook Page 38 of /30/07

39 VII. Weekly Data Processing Manual Data Entry Video 10 Manual Data Entry Traffic counts can be manually entered into SPS by selecting the Count tab under the SPS Current Database. A new window will open. It will display detail Records in the top portion of the screen and Summary records below. First clear any summary records, then add new data by selecting the Add a Count Summary Report icon (third icon to the right of Summary the icon looks like a sheet of paper). Type in the 2-digit county number, and the 4-digit site number, making sure to include leading zeroes. Type in the date in a MM/DD/YYYY format. Enter the alpha direction code--n, S, E, W or B. If the manually added count record is an estimate (most manually entered counts are), enter a Survey Type code of 0, and a Survey Program code of 1. Enter the AADT value, taking care to round estimates to the nearest 50, 100, or 1000 vehicles, depending upon the volume range. Enter an Edit Flag code of 0. When complete, upload the manual counts to the mainframe via the process described above. Traffic Monitoring Handbook Page 39 of /30/07

40 VII. Weekly Data Processing SPS EDITS PERFORMED SPS performs the following edits on the traffic data being processed: 1) Verifies the County-Station number is valid. 2) Makes sure the type of data (axle, vehicle, class) agrees with the Survey Type code in SPS PTMS Inventory. 3) Checks that the type of data being analyzed is compatible with the Sensor Type code in SPS PTMS Inventory. 4) Checks that the SPS PTMS Inventory agrees that the data being processed is from a portable counter, i.e. the Survey Program code of the data must be ) Compares the direction codes in the data to the ascending and descending directions in SPS PTMS Inventory. 6) Data from all lanes is present in the input files. 7) Checks the Station Inventory to ensure that the data is either directional or non-directional. 8) Checks for a minimum of 24-hours of data for each count 9) Are there any directional volumes equal to 0 between 5:00am and midnight? 10) Checks that no 4 consecutive hours have the same total 11) Checks that volume in one direction is not greater than 80% of the total volume. 12) Compares the daily volumes of the count being edited to the minimum and maximum variance factor values for the station for the month of year, taking into account whether the data is an axle or vehicle count. 13) Makes sure that hourly volumes do not exceed 2000 vehicles for 2-lane roads, or 2500 vehicles per lane on all others. 14) Checks that classification Types 1, 4, and 15 are not above specified percentage as identified by the user. Traffic Monitoring Handbook Page 40 of /30/07

41 VII. Weekly Data Processing Problems Problem Resolution If codes in the raw data file don't match codes in the Inventory, SPS can't load the count; or can't process it. The codes for the following items must match: 1) County/Site Number 2) Number of Lanes Ascending/Descending 3) Ascending/Descending Directions 4) Count by Direction 5) Count by Lane 6) Sensor Type 7) Survey Program 8) Survey Type Survey Type must agree with Sensor Type. Our Inventory currently utilizes the following codes for Sensor Type and corresponding Survey Type for short term counts: 1) Type 1 (Axle Counts) must be coded with Sensor Type 7 (Tubes) 2) Type 2 (Vehicle Counts) must be coded with Sensor Type 1 (Loops) 3) Type 3 (Classification Counts) must be coded with Sensor Type 7 (Tubes) or Sensor Type 5 (Two Loops and One Piezo) Errors occur when the field technician doesn t program the counters with the proper codes for Survey Program, Sensor Type, and Survey Type. 1) Counts obtained by a consultant must be coded for Survey Program 2 2) Sensor Type will be either 7 (road tubes) or Type 5 (2 loops and 1 Piezo) 3) Survey Type will be either code 3 (Classification) or code 1 (Axle) Often, the problem can be fixed by correcting the codes in the Inventory or raw data file. 1) To identify the problem, open the.prn or.txt file and compare it to the Inventory. 2) If you can t fix it, check your records before actually making a recount---the problem might be an incomplete or corrupted data file (for instance, maybe all the lanes were counted but are not being processed). If the site was classified last year, the Inventory will be coded Survey Type 3 and Count-by-Lane yes; the count won't load if data is missing for any lanes. This happens when: 1) This year's data is volume, not counted by lane 2) The number of lanes being processed doesn't match the number of lanes listed in the Inventory. 3) Data is missing for any lane. Traffic Monitoring Handbook Page 41 of /30/07

42 VII. Weekly Data Processing If the direction codes don t match, the count won t load: This most often happens when the ascending/descending direction isn't obvious to the technician in the field---for instance, a road might be Ascending N (1) and Descending S (5) according to the Inventory, but the segment of roadway where the count is taken might run NE and SW and the technician codes the count with E (3) and W (7). HINT: You can often save yourself research time by the way you describe the site location in the Inventory: in this case, if you have described the site as NE or SW of the intersection---you know that E is N and W is S, and you can correctly edit the data file. Remember to update the TCI Station Inventory Database codes to match the data you send to the mainframe or the SPS upload to mainframe will fail---with the one exception: the software will allow you to utilize more than one Survey Program for each site. ANALYZING THE DATA Acceptability of Data Even though you accept one or more days while performing preliminary edits, you should continue with your analyses to determine if all facets of your data appear reasonable. To analyze the count for acceptability, apply SF and AF from the previous year and compare it to historic data. Guidelines used to determine if counts are of acceptable quality will vary from site-to-site. There are no hard, fast rules because there are many variables that cause traffic characteristics to fluctuate. Each District will determine what constitutes a significant difference for each facet of each short-term count. For example, you might: 1) Define a specific range that you consider reasonable; for instance, from 20% under 5,000 AADT to 5% over 50,000 AADT. 2) Select a single percentage such as 10% for volume and 5% for classification categories. 3) Use a combination of methods. Start with a single percentage (such as 10%) for all preliminary screening. For counts that fall through the preliminary screen, continue your analysis by using other guidelines that include regional growth trends and conditions. 4) For a quick preliminary volume screen without applying Seasonal Factors: If the County s seasonal fluctuation varies by at least 20% between peak and off-peak, and you use 10% as your screening percentage, there is no need to apply SF unless the ADT varies from historic AADT by more than 20%. Traffic Monitoring Handbook Page 42 of /30/07

43 VII. Weekly Data Processing 5) If, in your professional judgment, your data fails any Acceptability of Data tests; you need to find out why it failed, and conduct further analyses until you arrive at a logical decision to accept, recount, or estimate. 6) During the Annual Data Processing activities described in Chapter VIII you will have the opportunity to re-evaluate your accepted counts using current year Seasonal and Axle Factors. (See Chapter VIII Annual Data Processing) Analyzing Raw Counts When analyzing your counts, keep in mind that the purpose of the annual traffic count program is to monitor traffic growth. Try to avoid significant traffic fluctuations that are due to temporary events such as road construction or severe weather. The data must be examined by direction, hour, and count interval (usually 15-minutes); from one day to the next and year-to-year. Conduct a preliminary analysis by utilizing reports produced by SPS, the PTMS Inventory Database, previous year AADT Report, Traffic Count Location Maps, Straight Line Diagrams, local street maps, and other counts obtained on adjacent roadway segments. Using the reports produced by SPS, look at the count itself. Usually the directional split will be close to equal, and the count will be similar for both days. Also look for incorrect directional relationships- --morning rush hour is usually toward town, evening rush is opposite. Consider changes that have taken place in the field, such as lanes added, changes in one-way pairs, road transfers, new intersections, etc. Compare the count to last year s AADT. Total volume and truck volume should be within reasonable increase or decrease of previous years counts, considering the season the count is taken and historic growth trends, providing there have been no significant changes in the field. If AADT appears to be significantly higher or lower than expected, find out if there have been temporary changes in the field that might have influenced the traffic. If changes are temporary (such as construction), don t use the count. If you can find no obvious reason for the change, apply the previous year s Seasonal and Axle Factors and conduct a more detailed evaluation. 1) Be aware that changes in one County can affect traffic patterns in another County. 2) Consider the possibility that our winter visitors moved to Florida early this year because it snowed earlier than usual, or they extended their stay in Florida to avoid a late snow up North. 3) Gas prices and the economy will influence travel. Don t automatically reject a count just because the total volume or truck volume shows significant change. If there have been numerous changes in your District, counts might not follow historic trends. Locate the site on a map and visualize how traffic would flow. Imagine yourself in various driving situations---what route would you Traffic Monitoring Handbook Page 43 of /30/07

44 VII. Weekly Data Processing take? It might be very obvious why the directional split is extreme, or why truck % or volume significantly differs from one segment to the next. Analyze each category of your classification counts according to your District s needs. In general, Federal Roads and Interstates require close scrutiny to produce accurate Classification and volume, State Roads require accurate T% and volume, Federal Aid (off-system) roads need accurate volume. 1) Except for classes 6 and 7 (due to dump trucks with lift axles), categories can be expected to be very similar by direction. 2) Most trucks are usually Class 9 vehicles---as much as 80-90% of traffic loadings on the interstate system. 3) There will be no numbers in category 14. 4) Class 11, 12 or 13 vehicles shouldn t be on roads where their use is not permitted or expected. For example, you can expect to see a lot of class 13 trucks traveling on the Interstate, but not on a 2-lane country road. 5) SPS creates error messages for counts with more than 3% in category 1, 5% in category 5, or 10% in category 15. Each District can adjust these defaults as they see fit. 6) Vehicles that could not be clearly classified are thrown into Category 15 when SPS creates the summary reports, these vehicles are added into category 2. A high number in category 15 is a good indication that the traffic was not properly classified---it is also a good indication that the PIEZO might be going bad. 7) Historic analysis will help you verify questionable volumes in the classification categories. 8) Be alert to corrupted data files in which the total of vehicles in classification categories does not match the hourly or daily vehicle total SPS currently doesn t catch this error. This error can most easily be found on the SPS Classification Summary Report or in the Record Summary Report (.RSR). Review the.syn Report to verify the following information. 1) AM/PM time: Occasionally a counter is set that reverses AM and PM resulting in a count that shows all the vehicles traveling during the night 2) Peak hours usually occur due to people traveling to work in the morning and home in the afternoon. 3) The Peak Hour Report produced by SPS is currently set by Planning requirements to assume the Peak Hour is from 5-6PM at all sites. This is not useful for analyzing accuracy of counts. 4) 15-minute intervals: There should be no 0 s during peak hours. 5) There should be no exceptionally high or low counts during any intervals. 6).SYN is the only report that shows T24 truck percentages, which can be verified with nearby class counts, other counts obtained at this site during the current year, and previous T%. Traffic Monitoring Handbook Page 44 of /30/07

45 VII. Weekly Data Processing Compare it to counts that were made in adjacent roadway segments, and on intersecting roadways. If you still question the validity of a count; conduct additional in-depth analyses using Historic Traffic Data, Videolog, and field review to consider long-term changes that are taking place in the field. Consult with people in other FDOT departments or local governments (MPO, County or City) who are knowledgeable about local conditions. SLD, field review, I-View and Videolog, can be helpful in identifying conditions that have influenced a long-term change in traffic characteristics such as: 1) Lanes added (this can be done by restriping as well as widening) 2) Changes in one-way pairs 3) Road transfers 4) New intersections/interchanges (especially on limited access roads) 5) New roads 6) New housing developments 7) Changes in land use. 8) Unusual configuration of one-way pairs can influence directional splits on other segments. 9) Truck routes divert truck traffic. 10) Traffic generators such as truck stops influence truck traffic. 11) When City Limits are moved, speed limits will change. 12) Orange groves can die causing sudden changes in traffic flow. 13) Over a period of years, mining operations open new entrances or move to new areas when the old mines are played out. 14) Truck patterns and type are heavily affected by local economic activity. 15) A high percentage of through trucks tends to result in higher weekend and nighttime truck traffic than on a road with a low volume of through trucks. This can cause significant differences in T% at TTMS s (which count all week) and T% at nearby Short Term sites (which count only weekdays). 16) Traffic flow exhibits more seasonal variation in recreational areas. 17) Traffic flow exhibits higher daily fluctuations in rural areas. You might need recounts, or additional counts later in the year, to help with your decisions. After you are reasonably confident that a count is of acceptable quality, send it to the mainframe. (See Chapter VII UPLOAD DATA TO MAINFRAME) Traffic Monitoring Handbook Page 45 of /30/07

46 VII. Weekly Data Processing Examples and Tips from the Districts Some or all counts and recounts along a roadway might show significant change for no apparent reason. After completing your analyses, what are your options for counts that remain questionable? 1) If you believe a change is temporary, and the count would significantly skew the history for the site; you can elect to reject the count and have Central Office provide an estimated AADT for the site. 2) If you believe the change is part of a new trend, or if you are still not confident in a count, you can elect to send the data to the mainframe and re-evaluate it during the AADT Development and Finalization process. 3) Follow-up during next year s count cycle to confirm your decisions and resolve remaining unanswered questions. Sites 2000 and 2002 are coded as Classification counts, and databases were submitted in the classification format. Volumes look reasonable, but these look like bad counts since there are 0 s in all categories except Category 2. What caused this to happen? Was the counter programmed wrong, was data lost? If classification is required, request a recount. Probably the counter was merely incorrectly coded for classification, but a volume count was collected- --in which case, you can recode the data file and accept it as a volume count. SPS won't load data for Site The error message reads "missing lane number 2 direction (E)." The classification data file submitted for this tube count has only 1 lane "E" and 1 lane "W" for this 4-lane location. Did the technician find a nearby 2-lane segment where the count was obtained? If so, you need to know where the count was made and why the site was moved. The site can be moved to the new milepost for a more accurate classification, you can use the same site number, if there is nothing between the old location and the new one that will cause a significant change in traffic characteristics (such as a truck stop or major intersection); otherwise, assign a new site number. If an axle count was submitted instead of a class count, change SPS PTMS Inventory SURVEYTYP code to 1, and change CntByLane code to F. If the site can no longer be classified with tubes, maybe this site is a candidate for permanent sensor installation. Site 5130, with an ADT of 5,900 each direction is a little low, but not low enough to reject the count. In the classification categories, however, there are several discrepancies: in category 3, SB is more than twice as high as NB; Category 6 NB is 10 times higher than SB; Categories 5, 8, 9, and 10 have similar differences. This site is located on a 2-lane road several miles from the Interstate, so we don't expect to see 410 vehicles in category 13. Nearby sites don't have this many Class 13 trucks---where did they all come from, and where did they go? Looking only at Category 13, the 410 vehicles (378 of them are NB) with 7 or more axles is potentially 1,435 class 2 Traffic Monitoring Handbook Page 46 of /30/07

47 VII. Weekly Data Processing vehicles---no wonder the ADT is low! You don't have to look any further to reject this data and request a recount. Maybe this site can no longer be classified. Is your PIEZO going bad? Sites 0108 and 0111 cause the error message "missing lane number 2 direction (E)." These volume counts are coded as classification. Change the SPS PTMS Inventory "CntByDir" code to "F" and the SURVEYTYP code to 1 and these records should pass the edits. Site 0079 NB on 3/5 the ADT was significantly (approximately 45%) lower than NB---historically, D is similar; so you should reject that day. On 3/6, NB and SB are similar and look reasonable according to last year's count. In the class data, however; there are 1002 class 6 trucks NB and 40 class 6 trucks SB. The Synopsis Report shows 1020 vehicles in one 15-minute interval. Since there was only a total of 2,641 vehicles for the day, request a recount. MAINTAINING EFFICIENCY AND ACCURACY Over time, traffic data must effectively document evolving traffic patterns, and identify local variations in traffic characteristics. The Districts will develop recommendations and modify their Traffic Count Program to maintain maximum efficiency and accuracy. 1) It might be desirable to count more frequently, or for longer count periods, at locations where traffic characteristics are rapidly changing. 2) Begin counting at additional sites as growth indicates. 3) As segments along a roadway become more homogenous, discontinue counting at some locations. 4) Consider locations for permanent sensor installation. 5) Unusual seasonal fluctuations might require an increase in counting frequency, or a modified count schedule. 6) Unique vehicle mix, or seasonal variations in truck percentage, might require more than one classification count per year. During analysis, you might realize the need to conduct counts at test sites to obtain supplemental data for current or future analyses. 1) Test counts will provide data for analysis of evolving field conditions. 2) Test counts can be used to follow-up on questions that weren t resolved to your satisfaction while analyzing currentyear counts. 3) If you wish, tests can be conducted every 2 or 3 years over a period of several years---the data can be kept in the mainframe database and a history can be built without assigning the test site to a section break. Traffic Monitoring Handbook Page 47 of /30/07

48 VII. Weekly Data Processing TRAFFIC CHARACTERISTICS INVENTORY DATABASE The official traffic database resides on the Department s mainframe computer, where it can be viewed by anyone in the Department. However, only authorized traffic count personnel may insert, delete, or change any data, or view the open-year traffic data. The Traffic Characteristics Inventory database is a DB2 relational database. It contains traffic station information, and historical and current year traffic volumes and vehicle classification data. Some traffic count stations have history stored as far back as The traffic databases on the mainframe are used frequently to make sure the short-term counts are valid and are processed correctly. Traffic Monitoring Handbook Page 48 of /30/07

49 VII. Weekly Data Processing TCI Traffic Characteristics Inventory Station Identification Video 11 Station Identification Stations Per Roadway Video 12 Stations Per Roadway The official Station Inventory is maintained on the FDOT mainframe computer. It contains information such as County, Station Number, Location, Directions of Travel, Number of Lanes, Survey Type, Survey Program, Sensor Type, Axle Factor Category, and Volume Factor Category. Each evening, the data in the Station Inventory is copied to a dataset residing on the mainframe. It is this copy that is downloaded by SPS and placed into an ACCESS table on the District PC. SPS can download this dataset whenever the operator desires. If the District operator does not want to wait until the following day to download the updated Station Inventory to the District PC, it is possible to change the particular piece of data in the SPS station inventory and continue to process the traffic data. However, the next time SPS downloads the Station Inventory from the mainframe, any changes made to the SPS station inventory will be overlaid. In order to avoid problems with the Weekly Load, be sure to update the mainframe Station Inventory database so it matches the information in the summary records. (See SPS EDITS PERFORMED and PROBLEM RESOLUTION) All the traffic count stations located along a particular section of road can be viewed using this transaction. The stations are listed in ascending order of station milepoint. The user can elect to display all stations, or just the active or inactive stations. The count year is optional. If entered, the transaction will display the AADT of the selected count year. This transaction can make a nice ad-hoc report of the traffic volumes on a particular road. Station Counts The detailed traffic count data are stored in this traffic database. It contains the date and direction of the count, and its raw and adjusted values. Anyone can look at this historical data, but only traffic count personnel can view the data for the current open year. A quick look at this database can confirm that a load job has run successfully. Video 13 Station Counts Traffic Monitoring Handbook Page 49 of /30/07

50 VII. Weekly Data Processing Volume Statistics The processed traffic data is stored in the annual count database. The data is stored by county-station and year. It consists of such items as the AADT, K, D. and T factors, and the peak hour information. This data is updated annually. Video 14 Volume Statistics AADT History Historical Annual Average Daily Traffic volumes are saved in the TCI database. The database contains traffic from as far back as 1970 for some stations. This data can be viewed by specifying the six-digit count station number, and the earliest year for which data is desired. The transaction will return traffic volumes from the entered year (or next closest stored year) forward to the latest year. Video 15 AADT History Monthly ADT This table stores the monthly ADT values for the continuous counters only. The monthly ADTs are stored for each direction of travel at the station. Video 16 Monthly ADT Class Detail The 24-hour summaries of each type of vehicle, and the daily total volume are stored for each direction, lane, and date for each class station. Video 17 Class Detail Vehicle Statistics Video 18 Vehicle Statistics Vehicle History Annual vehicle summary class data is stored in this database table. It contains the annual percentages of traffic by each vehicle class, the annual T factor (daily truck percentage), and the design hour heavy, medium and total truck percentages. This data is updated annually. The annual class summary data are displayed on this Inquiry Only screen. The 15 Modified Scheme "F" vehicle classes are collapsed into just 4 groups (passenger vehicles, single-unit trucks, semi-trailer trucks, multi-trailer trucks) in order to fit on the screen. The percentages are multiplied with the AADT to calculate the numbers of vehicles in each group. Video 19 Vehicle History Traffic Monitoring Handbook Page 50 of /30/07

51 VII. Weekly Data Processing Seasonal Factor Category Video 20 Seasonal Factor Axle Factor Category Video 21 Axle Factor Seasonal Weekly Adjustment Factors Video 22 Seasonal Factors Axle Weekly Adjustment Factors Seasonal factor categories are those groupings of continuous count stations whose data will be used to develop the factors that will adjust short-duration counts for the time of year. The category is a four digit number the first two digits are the county codes, and the second two digits are a user supplied sequence number. It contains a verbal description that informs the user of its intended use, and a maximum of eight continuous count station numbers. The End-of-Year processing programs calculate the appropriate factors from the data collected at the stations assigned to the factor categories. It is best if multiple stations are assigned to a factor category, so that reasonable factors can be calculated even if a single station is not counted that year, or if it is counted but has atypical traffic. Axle factor categories are those groupings of vehicle classification stations whose data will be used to develop the factors that will adjust axle counts into vehicle counts. The category is a four digit number the first two digits are the county codes, and the second two digits are a user supplied sequence number. It contains a verbal description that informs the user of its intended use, and a maximum of eight vehicle class stations. Both short-duration and continuous class stations can be assigned to axle factor categories. The End-of-Year processing programs calculate the appropriate factors from the data collected at the stations assigned to the factor categories. It is best if multiple stations are assigned to a factor category, so that reasonable factors can be calculated even if a single station is not counted that year, or if it is counted but has atypical traffic. The weekly seasonal adjustment factors are stored in the database and displayed with this application. There can be from 52 to 54 weekly factors, depending upon which day-of-week January 1 falls. The seasonal adjustment factors are multiplied with the raw count to derive an AADT estimate. If the seasonal factor is greater than 1, that means the count was collected during a time of the year when the traffic volumes are low, and must be raised to reach the annual average. If the seasonal factor is less than 1, the raw count was collected during a time of year when the traffic volumes are high, and the raw count must be lowered to the annual average. The weekly axle adjustment factors are stored in the database and displayed with this application. There can be from 52 to 54 weekly factors, depending upon which day-of-week January 1 falls. All axle adjustment factors are less than or equal to 1. The axle adjustment factors are multiplied with the raw count to lower axle counts into vehicle count estimates. Video 23 Axle Factors Traffic Monitoring Handbook Page 51 of /30/07

52 VII. Weekly Data Processing District Jobs Resubmit Load Video 24 Resubmit Load Occasionally, traffic data uploaded from the District PC to the mainframe will fail to load into the TCI database. This happens when the mainframe load program detects an inconsistency between the submitted data and the information in the database tables. Often, this is attributable to a minor difference in codes (say Survey Type or Survey Program) and can be easily corrected. This screen allows you to edit the file containing the rejected records, change the incorrect codes, and then save and resubmit the corrected file. This can be a significant timesaver when the data is rejected for a minor problem. If there are substantial problems with the data, it is best to return to the Survey Processing Software, make required changes, and re-upload the data to the mainframe. Traffic Breaks Per Roadway The Section Breaks Database contains the milepost limits of the traffic break segments as defined by District personnel, and the station at which the traffic for that break is counted, and a flag indicating whether that station is located within, adjacent to, or off the traffic break segment. Traffic section breaks are defined for each traffic count cycle. They are used to distribute the traffic volumes taken at a specific point (i.e., station) to a length of highway (i.e., section). Video 25 Traffic Breaks Station Inventory Report This Tab produces a report of the traffic monitoring stations for the District and station status selected by the user: Video 26 Station Inventory Report Traffic Monitoring Handbook Page 52 of /30/07

53 VII. Weekly Data Processing AADT History Report This tab produces a report of the AADTs for the selected years and stations: Video 27 AADT History Report Raw Counts Report This tab produces a report of all the raw counts that have been saved in the database for the selected year and stations: Video 28 Raw Counts Report Traffic Monitoring Handbook Page 53 of /30/07

54 VII. Weekly Data Processing Monthly Continuous ADT Report This tab produces a report of the monthly ADTs for the selected years and stations: Video 29 Monthly Continuous ADT Report Traffic Monitoring Handbook Page 54 of /30/07

55 VII. Weekly Data Processing Traffic Flow Break Station Video 30 Traffic Flow Breaks The traffic flow breaks are stored and maintained in RCI Feature 330. The user must enter the roadway ID (county,section,subsection) of the desired road. RCI will return a list of all traffic break segments that have been identified along this road. Each traffic break consists of the beginning and ending milepoints of the break, and two characteristics: FLWBRKID (count station assigned to the traffic segment) and TRFBRKCD (count station code). If the beginning and ending milepoints of a traffic break segment are tied to an intersecting road (RCI Feature 251), when the roadway is shortened or lengthened (due to a re-inventory), then the milepoints of the traffic break are automatically adjusted correspondingly. This keeps the traffic breaks synchronized with RCI so that the AADT, K, D and T can be easily placed into RCI Feature 331 at the conclusion of the annual traffic data processing cycle. Traffic Monitoring Handbook Page 55 of /30/07

56 VIII. Annual Data Processing VIII. ANNUAL DATA PROCESSING Video 31 AADT Development Between January 1 and March 15 each year, the Districts and the TRANSTAT Central Office work together to evaluate and finalize traffic count data that was loaded to the mainframe during the previous calendar year. This process includes factor development and assignments, and application of appropriate factors to traffic counts. AADT, K, D, and T are estimated for every section break of the State Highway System. Unless otherwise stated, K and D are for the 30th highest hour of the year based on data from continuous monitoring sites. During this end-of-year Annual Statistics Development Process, TRANSTAT produces several reports to help the Districts analyze short-term data and update databases. TRANSTAT coordinates this process within strict deadlines. Review the QC Plans in Appendices F and G, and flow charts and QC plan deadlines. CONTINUOUS COUNT DATA Monthly ADTs The TRANSTAT Office processes the continuous count data to develop the Monthly Average Daily Traffic (MADT), Annual Average Daily Traffic (AADT), and monthly factors. Monthly ADTs are computed in the following manner: 1) Each direction of travel at each site is processed separately. 2) Only daily records with flags of N (normal), A (atypical), H (holiday) and S (special event) are used. Any records flagged B (bad) are not used in any calculation. 3) For each month, all the Mondays, Tuesdays, etc. are averaged. 4) The monthly ADT is computed by averaging the seven dayof-week averages. Note, if a Saturday or Sunday average is unavailable for a particular month, then that monthly ADT is not calculated. However, if both the Saturday and Sunday, and at least one weekday averages are available for a month, the monthly ADT will be computed based on the averages of available days. AADT Annual average daily traffic are computed in the following manner: 1) The monthly averages for each day-of-week are averaged to generate the annual day-of-week averages. 2) The seven annual average day-of-week values are averaged to generate the annual average daily traffic. 3) The directional annual average daily traffic volumes are summed to generate the annual average daily traffic for a station. Traffic Monitoring Handbook Page 56 of /30/07

57 VIII. Annual Data Processing Seasonal Adjustment Factors FACTOR CATEGORIES ASSIGNING STATIONS TO CATEGORIES Seasonal (volume) adjustment factors are calculated in the following manner: 1) Each direction of travel at each site is processed separately. 2) Monthly ADT are estimated for those months where data is lacking. Missing monthly ADT will not be estimated for those stations missing more than 2 consecutive months of data. 3) Monthly factors are computed by dividing the AADT by the MADT. 4) For each station, the directional monthly factors are averaged together. For those stations that have only one good direction of data, those monthly factors are used for the station. Each year, changes in the number and type of counts result in the need to update the Assignment of Stations to Categories, and the Assignment of Categories to Counts. During the AADT DEVELOPMENT PROCESS, the Districts work closely with the Central Office to make certain the correct assignments are made, and the Inventory Database is updated. Seasonal and Axle Factors are applied to short-term counts to estimate AADT. District staff assign up to eight stations to each factor category, so that reasonable factors can be calculated even if any stations are not counted that year, or if it is counted but has atypical traffic. Assignments to categories can be made anytime throughout the count year cycle by using the Seasonal or Axle Factor Category Assignment screens available under the FCAT tab on the mainframe TCI application. Seasonal Factor Categories It is recommended that more than one count station be assigned to each factor category so that a fair representation of the traffic s seasonal flow and volume can be estimated. Seasonal categories have been designed to be county specific with at least one Seasonal Category Statewide Category for each County and one Seasonal Factor Category for each Interstate Roadway within each County. Additional Seasonal Factor Categories can be developed to handle geographic differences within a single county (For example beach traffic has different characteristics than urban traffic). Axle Factor Categories Axle factor categories are handled similarly to seasonal factor categories, except both TTMS and PTMS classification stations can be assigned to axle factor categories. Axle factor categories are more highway-specific than seasonal factor categories---an Axle Factor Category must be developed for each Highway Section. This results in considerably more axle factor categories than seasonal factor categories. Traffic Monitoring Handbook Page 57 of /30/07

58 VIII. Annual Data Processing COMPUTING SEASONAL AND AXLE FACTORS: ASSIGNING CATEGORIES TO COUNTS UPDATE FACTOR CATEGORIES Central Office derives axle factors from classification counts by dividing the total volume of vehicles by half the number of axles present on those same vehicles. This results in a factor that is always less than 1.00 (although it may round to 1.00 if there are few trucks in the traffic stream). 1) All stations assigned to the factor category are averaged together to generate monthly average factors. 2) The monthly average factors are assigned to the week of the year that contains the midpoint of the month. 3) Weeks without factors are estimated by extrapolating from the mid-week of one month to the mid-week of the next month. Seasonal and Axle Factors are assigned to each count by SPS when counts are processed---according to the information contained in the Station Inventory Database. These assignments must be reviewed and updated during the AADT Development Process---with special care given to stations with more than one type of count. 1) Seasonal and Axle Factor Categories and assignments can be updated at any time throughout the year. 2) At least one continuous count station (TTMS) must be assigned to each Seasonal Factor Category. 3) At least one seasonal or continuous class station must be assigned to each Axle Factor Category. 4) A Seasonal Factor Category must be assigned to each shortterm monitoring site. 5) An Axle Factor Category must be assigned to each shortterm monitoring site. 6) Assign class stations to any axle factor category for which no axle factors can be calculated because of lack of data. Traffic Monitoring Handbook Page 58 of /30/07

59 VIII. Annual Data Processing FINAL REVIEW After updated factors are applied, reports are generated and a final review is done. 1) Review the factored counts to make sure that the correct seasonal and axle factor categories are applied to each count depending upon the type of count, the sensor type, and the Survey Program. 2) If multiple counts are taken throughout the year at the same count station, it is possible that different seasonal or axle factor categories have been assigned to each count, depending on whether or not changes have been made to the Seasonal or Axle Factor Category assigned to a count station in TCI. If this occurs, manually change the incorrect factor category assigned to the count by using the TCI Count Data update screen. All counts at the same station should use the same Seasonal Factor Category for the count year. If there are multiple axle counts loaded for a single station during the year, the same Axle Factor Category should be assigned to each. 3) Make sure all factors are applied as desired, and make adjustments to sites for which the resulting AADT s are not reasonable. 4) Make sure all desired count sites are activated in TCI and deactivate sites that won t be used. 5) Make sure all counts are correctly included in the current year database. Districts can manually add, delete, or change count summaries from the Count Data screen in TCI. 6) Compare the directional split to historic counts and to adjacent counts to make sure they are reasonable. 7) Verify that any AADT that is 20% lower or higher than the previous year AADT is in fact a legitimate value, and not an error. 8) All counts must either be directional or bi-directional at each site. 9) Review truck volumes and %T to make sure they are reasonable. If truck volumes weren t collected at a site, or aren t reasonable, the Districts can assign T% from another site (called a cross-reference ). 10) K, D, and T assignments not made at the District level will default to a Statewide Functional Classification Category. Traffic Monitoring Handbook Page 59 of /30/07

60 VIII. Annual Data Processing ESTIMATES ANNUAL STATISTICS Any active stations not counted during the year will have their AADT estimated by applying a growth factor (as obtained from the continuous counter data) to the previous year s AADT. Estimated AADT values will be computed for a maximum of two years in a row. Each station is to be counted a minimum of once every three years. When a site can t be counted for a third year, the site will be deactivated in the Station Inventory and a station from a break with similar traffic characteristics will be assigned to the break. If they wish, the Districts can manually estimate an AADT for the third year. An AADT, K, D and T factor must be assigned to each count station. T factors can be calculated for all vehicle class stations. K and D factors can only be calculated for continuous count stations with sufficient quantities of good data. For all other stations, the K30, D30 and T values are estimated, based on the following methodology: Continuous Monitoring Short-Term Monitoring Sites Choice by Sites Priority K and D T K and D T 1st Seasonal Factor Category Cross Reference Seasonal Factor Category Axle Factor Category 2nd Functional Classification Category 3 rd Statewide Functional Classification Category Axle Factor Category Districtwide Functional Classification 4 th _ Statewide Functional Classification Districtwide Functional classification Category Statewide Functional Classification Category _ Districtwide Functional Classification Category Statewide Functional Classification Category _ SECTION BREAK STATISTICS In order to assign an AADT, K30, D30 and T factor to all highways in the RCI database, the section breaks file is used. This file is used to assign data collected at a particular point of the road to a length of highway. Section breaks development is done after the AADT, K30, D30, and T values are finalized for each station. This involves review of the Breaks File on the Mainframe and the Breaks with no AADT Report for proper break points and station assignments. District personnel develop section breaks as previously described in Chapter V. These section breaks can be entered or modified in the Section Breaks File (RCI Feature 330) at any time during the count year. One, and only one, count station must be assigned to each traffic section break. The TRANSTAT Office will compare the updated traffic section Traffic Monitoring Handbook Page 60 of /30/07

61 VIII. Annual Data Processing ROLLOVER breaks file to the RCI database and provide a list to the Districts of any traffic break segments that must be modified to exactly match the current RCI database. Once the files are in agreement, TRANSTAT will submit the job to delete all the traffic data in RCI feature 331, and replace it with the new traffic data. The final step in the AADT development process is carried out by TRANSTAT. This consists of adding the finalized traffic data to the mainframe TCI databases, closing the old count year, opening the new count year, and copying the axle and seasonal factor categories (and station assignments) and the section break files into the new count year tables. DATA DISTRIBUTION After the section break traffic is finalized, usually by April 1, TRANSTAT closes the databases so no more changes can be made. The Districts can then begin uploading SPS count summaries for the new count year. After TRANSTAT completes Rollover, no further changes can be made to the data for the year just closed, and this official data is made available for distribution and use until the next annual update. The Florida Department of Transportation Annual Average Daily Traffic Reports (a separate AADT Report for each County in the State of Florida) are placed by TRANSTAT on the FDOT web page at These reports contain AADT, K 30, D 30, and T for every Section Break on the State Road System. Traffic Count Location Maps for each county are also on the web page. Since there is too much traffic data to get it all on our web page, FDOT TRANSTAT also produces an annual Florida Traffic Information disk which contains the AADT Reports and associated Traffic Statistics, including Historic AADTs and 24-hour traffic counts in 15-minute increments (Synopsis Reports). The disk may be obtained free of charge from any District or TRANSTAT. Data can also be accessed directly from RCI and TCI by users that have access to the FDOT mainframe computer and possess a valid USERID and password. Traffic Monitoring Handbook Page 61 of /30/07

62 IX. TTMS/PTMS Field Inspection and Inventory IX. TTMS/PTMS Field Inspection and Inventory Process Overview Video 32 Process Overview Introduction This chapter details the procedures and equipment used in the field when inspecting new and existing traffic monitoring sites. Throughout this handbook we have referenced the various types of Traffic Monitoring Sites (TMS) that make up the over 5,000 locations statewide where traffic data is collected on a regular basis. Two categories of traffic monitoring sites have permanent equipment physically located in the roadway. They are the backbone of the traffic count program administered by the Florida Department of Transportation Central and District offices. Specifically, the 300 Telemetered Traffic Monitoring Sites (TTMS) are the locations that are polled via modem daily by the TranStat Central Office Computers. They record and transmit every day of the year and provide the data used for adjusting short-term traffic counts to Annual Average Daily Traffic (AADT). The second member of the permanent count family is the Portable Traffic Monitoring Sites (PTMS). These locations are usually installed on high volume urban arterials where rubber hose counts or other equipment are difficult to install and maintain. The permanent parts of the installation are the in-pavement sensors (loops and/or piezos) and the traffic cabinet. Greater reliability and accuracy are the reason loops are preferred to hose counts. A traffic counter is normally placed in the cabinet and attached to the wire harness for a short period (3-7 days) either annually or quarterly then moved from one site to another, hence the term portable traffic monitoring site. Some locations are in rural or urban fringe areas that are located for coverage counts on roads that have the potential for significant increases in traffic as development and new traffic patterns evolve. Others are located for safety reasons as the difficulty in installing temporary equipment is dangerous due either to high travel speeds and/or roadway volumes. Background The State Road Department started collecting data at ten locations back in As the state grew both in population and number of lane miles, the need to expand traffic data collection was obvious. The value of good data became apparent early on in the evolution of the national Department of Transportation (DOT) and eventually the Federal Highway Administration (FHWA). This data translated into revenue allocations for the state and federal highway programs. A significant portion (approximately 25%) of TTMS locations is on the Interstate Highway and Florida Turnpike. The remainder are located on US Highways and major state roads. The data collected at these sites may include: volume, speed, vehicle class and weight. Some sites collect only volume or speed Traffic Monitoring Handbook Page 62 of /30/07

63 IX. TTMS/PTMS Field Inspection and Inventory Installation and Maintenance Responsibility Field Inspections of Traffic Monitoring Sites At the Site while others collect combinations of all categories. The type of equipment installed and the programs set-up in the equipment determine how the site functions. The purpose of all the sites is to provide the Department with a basis to meet the reporting requirements of the FHWA for sustaining the funding of federal transportation programs and to provide critical data required for engineering analysis of existing facilities and to identify the need for expansion in the roadway network. FDOT Central or District Offices determine when and where new sites are required. Often times when major highway construction projects are undertaken, a count site will be included in the design plans at the request of the Statistics Department. Normally, 3-4 new sites are installed each year and several others receive equipment upgrades. The type of equipment installed is determined by the type of data desired. As stated previously, the TTMS locations come under the control of the Central Office Statistics Department while the PTMS sites are the responsibility of each District Office. The customary procedure is to provide the site location and equipment information in the design plans as specified in the Roadway Design Plans Standard Index through Each set-up has a list of pay items and details of how the installation must be constructed in order to function properly. The acceptance of the installation by the Department is determined after field inspection and inventory by a qualified technician completing the procedures outlined in this chapter. The next sections of this chapter detail the field inspection and inventory requirements of TTMS and PTMS sites. The process begins with a request or work order from the Central Office (TTMS) or District Office (PTMS) for a field inspection and inventory of equipment at a new or existing site. Once the work order is initiated, a trained service technician makes a visit to the site to ensure the correct equipment is installed and working as specified by the design request of the District or Central Office. The following steps outline the recommended process that should be used by all technicians when inspecting and inventorying a TTMS or PTMS site. The significant difference between TTMS and PTMS sites is the telephone connection with modem required for transmitting the data daily and the solar panel that supplies power to the battery. PTMS sites may have the same cabinet, counter harness, loop diagrams and internal panels as a TTMS site, but does not have the need for continuous power or communications. Two forms are required by the Department to be completed at each installation by the field technician to update the count site database. They are: TTMS Inspection Sheet and TTMS Inventory log (copies attached). We will step through the process of completing each of these reports and provide both video and still photo examples of the procedures and equipment used and installed at the sites. Upon arriving at the field site, the technician should follow the standard procedures described earlier in this handbook for exiting the roadway safely by activating turn signals and flashers in advance of the site and pulling completely off the road and whenever possible providing the maximum amount of separation from the travel lanes Traffic Monitoring Handbook Page 63 of /30/07

64 IX. TTMS/PTMS Field Inspection and Inventory Sensor Configurations Check condition Video 33 Check Conditions Check Layout and clear zones of the roadway. The technician should have an orange safety vest on prior to or immediately after exiting the vehicle. It is important to always proceed slowly and cautiously when working at any location adjacent to the highway. This is especially true when working alone, as in the case with most field inspections at TTMS or PTMS sites. Try to always face oncoming traffic whenever making field measurements and checking in-road devices or those adjacent to the travel lanes. Be Alert. The procedures provided here require operating knowledge of oscilloscopes, volt-ohm meters, telephone connections and basic wiring. Voltages are low and therefore electrical shock is not a concern, however, damage to components from improper use or incorrect connection of testing equipment should be considered at all times. Examples of some of the equipment used in testing the equipment are provided here. They may have appeared in other areas of this document, as they are common to the technician and his tasks. Photos or videos of most of the equipment types and procedures used are provided to assist in identifying components and safe practices. All models or manufacturers may not be represented in the samples provided as some are being phased out as newer and more efficient replacements become available. Visually inspect loops and piezos for rutting & cracking, or breaks. If cracks allow water to surround the leads, it may interfere with the operation of the sensors. When checking the depth of cracks or missing sealant, don't use a sharp object like a screwdriver or pocketknife to probe as it may result in equipment damage. Loops should be centered in the lane and perpendicular to lane stripes. The piezo sensor should be located between the loops. It is positioned to cover only a single wheel path. Measure Spacing With a wheel or tape measure, check loops to ensure that spacing is 16 feet from leading edge to leading edge. Each loop should measure 6 feet. The piezo should be 1 foot after the trailing edge of the first loop. Always wear a safety vest, and follow safety precautions when working on or near the roadway. Never turn your back to traffic. Traffic Monitoring Handbook Page 64 of /30/07

65 IX. TTMS/PTMS Field Inspection and Inventory Check Sealant & Grout Check Pullbox Video 34 Check Pullbox Check that the loop slot is filled with sealant. The piezo grout should be smooth. The peizo grout should be even with or slightly higher than the pavement surface. If the peizo grout is concave, the sensors will not record correctly. G100 Epoxy is not allowed for piezos installed in asphalt. Check the pullbox for correct installation. The pullbox should be located a minimum of 8 feet from the edge of the pavement. Lids should be level with the surrounding surface. Inspect the concrete box for cracks to ensure it is intact. A pull box should be sitting on a 12 to 15 inch gravel base to allow proper drainage. This pullbox should be replaced. The loop wires should be spliced. The stranded 12 gauge wires should be spliced by soldering or crimping to a 12 gauge home run cable that is grounded in the cabinet. The peizo wires should not be spliced but simply passed through directly to the cabinet. They should all be encased in water seals. Cabinet Inspection Take photo Video 35 Cabinet Inspection Take photos of the site to indicate the type of cabinet and how it is mounted. The photos are a visual record of the condition of the cabinet and current inventory. Check fasteners Check that the cabinet is securely fastened and that it is good and tight. There should not be any rust on bolts, nuts or brackets. Check height Check seals The center of a pole mounted or break-away pedestal cabinet should be 4-feet above the ground. A low based mounted cabinet sits on a 3.5 inch concrete platform. Ensure that all entry holes are sealed against water and insect intrusion. Traffic Monitoring Handbook Page 65 of /30/07

66 IX. TTMS/PTMS Field Inspection and Inventory Measure ground rod Video 36 Measure Ground Rod Check wiring harness Measure and record ground rod resistance using an earth megger Clip the leads to the two ground rods and push the rods into the ground as far as they will go. The two ground rods are connected to the earth megger, and the red wire is connected to the cabinet ground. A good reading is less than 25 ohms. However, state specifications only require a 50' ground rod. Older PTMS sites may not have ground rods to measure. Care must be exercised in using the earth megger because it outputs up to 500 volts which may damage components within the cabinet. It may also give you quite a jolt. Check that the wiring harness is installed. Locate diagram Record GPS Video 37 Record GPS Locate and verify that the sensor wiring diagram was left by the contractor in the cabinet. Be sure the diagram is written directly on the cabinet door. If GPS coordinates have not been recorded for a site, Measure and record them. The GPS coordinates will help technicians locate the cabinet and ensure that the GIS maps are accurate. Once the GPS unit has a signal from all four satellites, it displays the Latitudinal and Longitudinal coordinates. Output should be expressed in degrees with five decimal places to be consistent with the database. Traffic Monitoring Handbook Page 66 of /30/07

67 IX. TTMS/PTMS Field Inspection and Inventory Check Loops Video 38 Check Loops Label leads Measure loop resistance Measure loop inductance Measure loop leakage Make sure that all loop and piezo leads are clearly labeled. The leads are labeled here by the number of yellow bands wrapped around the cable. To test the series resistance of a loop, hook the Inductive loop analyzer across the loop itself. Remove the loop from the terminal strip to measure. State specifications require less than 10 ohms, but a good loop measures less than 3 ohms. The meter also measures the inductance, which should be a minimum 100 microhenries. To measure the loop leakage to ground, disconnect both leads of the loop from the terminal strip. Connect one of leads of the megger to the loop wire and the other lead connected to ground. When you push the meg button, the meter should read greater than 100 megaohms. Remember to reattach and securely tighten the leads to the terminal strip after testing. Check Piezos Video 39 Check Piezos Measure voltage output Remove the piezo coax cable from the terminal strip. The ground side of the coax cable is wrapped around the center conductor. Connect the center conductor to the probe side and the ground side to the ground side of the oscilloscope. The oscilloscope amplitude is set to 100 millivolts per division on the front of the scope. The trigger is set to 100 miliseconds and is set to trigger on the leading edge of the pulse. Measure voltage output on the oscilloscope The pulse should be greater than 100 millivolts for a car. Measure capacitance Run a meg test for capacitance and resistance. Set the megger at 500 volts. The piezo should read more than 20 megaohms. If the resistance is less than 20 megaohms, the peizo should be replaced. The capacitance of a newly installed piezo should be within plus or minus 20% of the factory certified measurement. If needed, the capacitance can be estimated based on the length of the piezo and cable. Traffic Monitoring Handbook Page 67 of /30/07

68 IX. TTMS/PTMS Field Inspection and Inventory Check Communications (TTMS Sites Only) Video 40 Check Communications Check Phone Check Modem Check the phone line by unplugging the modem and plugging a test phone into the telephone suppressor. Listen for a dial tone. There should be no noise or static on the line. Press any number key. It will break the dial tone. Listen for a quiet line. (Measure and record voltage 48 volts DC.) To check the polarity, plug the tester into the phone suppressor. If light number 3 lights, then the polarity is OK. If no other leds light, then there is no AC on the line. Check the modem. The modem is connected to the counter by this cable. Record equipment type and serial number. Check power and ground. Connect the modem to a laptop using a modem cable. The software tests the modem to verify that it is properly working. When you press enter, it flashes that the modem is OK, and then clears. Check the modem connections to both the phone lines and the counter. Use a cell phone to call the modem and check for a response. Remember to plug the modem back in when finished. It may save you a return trip! Traffic Monitoring Handbook Page 68 of /30/07

69 IX. TTMS/PTMS Field Inspection and Inventory Check Power Video 41 Check Power Solar Panel Use a compass to ensure that the solar panel points south or southwest. The proper angle for the solar panel is latitude plus 10 degrees. Visually inspect overhead lines, cables and trees. They should not shade the surface area of the solar panel. Disconnect the solar panel from the regulator and verify that it produces volts DC. Connect the regulator and verify that the output voltage reads volts DC on a sunny day. Check Battery Check the battery to be sure that is providing power. Testing this battery under load shows a reading of about 14.1 volts. Measure and record type and amperage. 100 amp/hr is required. Verify that the voltage doesn t drop below 12 volts DC when placed under a 3.5 amp load. Here we connect a light for 60 seconds. The voltage dropped from to an acceptable Within a minute the voltage had returned to This is a good battery. Traffic Monitoring Handbook Page 69 of /30/07

70 IX. TTMS/PTMS Field Inspection and Inventory Backplane Video 42 Check Wiring Harness The wiring harness connects to the terminal strips that connect to the loops and peizos. The harness ends in a 26 pin connector which is connected to the counter. Wiring harness 26 pin, PAT (WIM), or PEEK. Surge Suppressors Tomlinson, Edco, PEEK, none. Check Counter Video 43 Check Counter Diamond = TrafMan Peek = TDP/TOPS PAT = PAT RDC Record the equipment type, NH number, and serial number of the counter. Connect the laptop to the counter by disconnecting the cable connected to the modem and connecting it to the laptop. Run the compatible software program for the equipment typed. After it begins to communicate with the counter you will be prompted to enter the password. Check that the information coming from the counter is correct. Set time for correct time zone and count interval (15 or 60 minute). Check each lane for accurate class, speed and count data. Test sensors to see that the loops and peizos are sending signals. Monitor Traffic Data for 30 to 45 minutes to visually verify that the data being collected seems reasonable. This program displays the lane number, the exact time the vehicle is counted, the speed, number of axles, length Axle bin, speed bin, and the length between axles. The Distance between the back axles of a semi-trailer are typically 3.9 to 4.1 feet. Call the Tallahassee Springhill Facility for on-line testing. at The technician will replicate an on-line dial-up and verify that a signal is transmitting the data. Traffic Monitoring Handbook Page 70 of /30/07

71 IX. TTMS/PTMS Field Inspection and Inventory Peek 241 A Diamond Peek ADR3000 MetroCount Jamar Final Re-Check Video 44 Final Re-Check Prior to closing the cabinet, check that all tools and test equipment have been removed and all cables and connections are secure. It may save you the inconvenience of coming back to simply plug a modem back in. Ensure that all paper work for the site is in the plastic bag or pocket attached to panel door. Be sure that all fields are completed and proper equipment type is circled on both forms. Take digital photos of installation, location, cabinet mounting and signage. Submit the photos with completed paper work to the FDOT Springhill facility for database updating. Return all tools and test equipment to your vehicle and secure them for safety while your vehicle is in motion. Tag any equipment that is faulty for return to FDOT Springhill Road facility. Be sure that flashers and turn signals are used to safely re-enter the traffic stream when traffic permits. Traffic Monitoring Handbook Page 71 of /30/07

72 IX. TTMS/PTMS Field Inspection and Inventory Future Additions Future additions to this document will include trouble-shooting basics when a site has problems. As each occurrence may be something unique, standard procedures based on documented service reports will provide the background to suggested service routines and best practices. Traffic Monitoring Handbook Page 72 of /30/07

73 X. Reference Manuals 9BX. Reference Manuals AASHTO Guidelines for Traffic Data Programs AASHTO Highway Capacity Manual (HCM) - Transportation Research Board Manual on Uniform Traffic Control Devices (MUTCD) Project Traffic Handbook - Florida Department of Transportation Project Traffic Procedure - Florida Department of Transportation RCI Handbook - Florida Department of Transportation Standardization of Count and Classification Equipment Set-Up and Configuration Process Florida Department of Transportation Traffic Monitoring Guide Federal Highway Administration Traffic Monitoring Procedure Florida Department of Transportation Survey Processing Software (SPS) Florida Department of Transportation Traffic Monitoring Handbook Page 73 of 104 8/31/07

74 APPENDIX A Traffic Monitoring Equipment Certification Traffic Monitoring Handbook Page 74

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78 APPENDIX B FHWA Classification Scheme F Medium Trucks T 24 24T 24T+B = Heavy Trucks Large Trucks CLASS. GROUP Any 7 or more axle FHWA 14 Not Used Scheme F Traffic Monitoring Handbook Page 78

79 APPENDIX C Standard Index Loop Installation Details Traffic Monitoring Handbook Page 79

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82 APPENDIX D Standard Index Cabinet Installation Details Traffic Monitoring Handbook Page 82

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84 APPENDIX E Standard Index Traffic Monitoring Site Details Traffic Monitoring Handbook Page 84

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94 APPENDIX F AADT Development Flowchart AADT Process Data sources TTMS AADT, factors PTMS District Collects/edits data assignment Axle Correction Factors Seasonal Factors Traffic Monitoring Handbook Page 94

95 Traffic Adjustment Data Sources Short Term Traffic Counts Permanent Permanent Portable Continuous Counts Continuous Classification & Weigh-in-Motion Counts Seasonal Classification (Four Seasons) Portable Axle Counters Portable Vehicle Counters Traffic Counts Traffic Classification Counts Average Traffic Classifications (Four Seasons) Actual AADT, K & D Traffic Adjustment Factors Seasonal Volume Factors Axle Correction Factors Percent Trucks T Transportation Statistics Office District Apply Axle Correction Factors Assign Apply Seasonal Factors Assign Estimated Central Office Activity District Office Activity D i s t r i c t TTMS (Average day of week for each month) Count, Class, Weight, Speed AADT Annual Average Daily Traffic PTMS (Daily Volume ) Count & Class Only Class Data determines Axle Relationship Seasonal Trend Axle Relationship SF Categories ACF Categories AADT Estimates DISTRIBUTION Assignment of SF & ACF Categories to each PTMS Site Revision of SF & ACF Categories REVIEW/APPROVAL DISTRIBUTION Traffic Monitoring Handbook Page 95

96 APPENDIX G FDOT Quality Assurance Monitoring Plan Traffic Monitoring Handbook Page 96

97 District Quality Control Plan 2001 PRIMARY FUNCTION: Traffic Data Reporting Critical Process: Data Collection Schedule Critical Requirements Compliance Indicators District QC Plan QC Tasks/Activities Complete traffic data collection scheduling annually. Provide district data collection schedule for PTMSs to be counted for the program year to Central Office by 1/31. A. Determine number of active sites and counties that are to be counted and send schedule to CO. A. Identify active sites as of December 31 for your district for next year s data collection. B. Prepare a summary report including the total number of active sites for each county. C. Prepare data collection schedule. District Traffic Data Reporting Quality Control Plan 2001 Page 1 of 5 Final 6/15/2001

98 District Quality Control Plan 2001 PRIMARY FUNCTION: Traffic Data Reporting Critical Process: Traffic Data Collection Critical Requirements Compliance Indicators District QC Plan QC Tasks/Activities 1. Traffic data will be collected for urban areas (minimum of one count per site per year). A. At least one weekday 24-hour continuous count per year will be collected for at least 90% of the total active urban sites. B. All routine data collection begins 1/1 and ends 11/15 for urban areas. A. Determine the number of active urban sites for which a 24 hour count was collected and notify CO of % completion. A-1. Determine total number and location of active urban sites. A-2. Compare loaded counts with the active site listing to determine that identified sites are counted. B. District will conduct its traffic data collection on or after 1/1 each year and complete on or before 11/15 each year. B-1. Manage & coordinate traffic data collection program to be conducted within prescribed timeframe. B-2. Obtain available raw counts from local gov ts & other FDOT departments. District Traffic Data Reporting Quality Control Plan 2001 Page 2 of 5 Final 6/15/2001

99 Critical Requirements Compliance Indicators District QC Plan QC Tasks/Activities 2. Traffic data will be collected for rural areas (minimum of one count per site per year). A-1. At least one weekday 48-hour continuous count per year will be collected for at least 90% of the total active rural sites. A-2. All routine data collection begins 1/1 and ends 11/15 for rural areas. A. Determine the number of active rural sites for which a 48 hour count was collected and notify CO of % completion. A-1. Determine total number and location of active rural sites. A-2. Compare loaded counts with the active site listing to determine that identified sites are counted. B. District will conduct its traffic data collection on or after 1/1 each year and complete on or before 11/15 each year. B-1. Manage & coordinate traffic data collection program to be conducted within prescribed timeframe. B-2. Obtain available raw counts from local gov ts & other FDOT departments. District Traffic Data Reporting Quality Control Plan 2001 Page 3 of 5 Final 6/15/2001

100 Critical Requirements Compliance Indicators District QC Plan QC Tasks/Activities 3. Equipment must be functioning properly. A. Equipment certifications will be sent to CO by 1/31 every year. A-1. District will submit either a summary or a detailed report of equipment certification by 1/31. A-2. District will maintain record of equipment certification by model & serial number for 3 cal. years. A-1. Schedule and complete testing of in-house equipment by December 1. A-2. Obtain equipment certification from consultants/contractors before count cycle starts. A-3. Update certification files as necessary. B. Inform CO of the number & location of new and/or replacement TMS installations needed for your District. B. Determine & document the opportunity or need to add new or replacement TMS installations. B. Monitor District construction or resurfacing projects for possible TMS installations. C. Inform CO of the number & location of TMSs requiring repair. C. Document the needed repairs to TMS s sites and inform CO. C. During the program cycle identify any TMS sites that require any repair. District Traffic Data Reporting Quality Control Plan 2001 Page 4 of 5 Final 6/15/2001

101 District Quality Control Plan 2001 PRIMARY FUNCTION: Traffic Data Reporting Critical Process: Development of the Average Annual Daily Traffic (AADT) Critical Requirements Compliance Indicators District QC Plan QC Tasks/Activities 4. Traffic data will be edited and processed in a timely manner. A. All counts will be edited and processed by 12/31. A. Complete final weekly load (NCTRAFF.FDF) into the mainframe and notify Central Office of completion by 12/31. A-1. Review raw counts before processing. A-2. Prepare or memo for Central Office by 12/31. B. AADT development will be completed by March 15. B. Review and edit adjustment factors and develop AADT according to the following schedule: 2) Central Office will send the required reports as identified in the Traffic Monitoring Handbook by 2/11 & the District will update the associated files and notify CO by 2/23. 3) Central Office will send AADT reports by 2/28 & the District will update the associated files and notify CO by 3/6. B-1. Review, update, and finalize factor assignments. B-2. Notify CO as critical steps are completed. C. Provide justification for 1st & 2 nd year estimates by 3/1 (if required), and prepare 3rd year estimates by 3/1 (if required). C. Identify active site for which no valid count was obtained. District Traffic Data Reporting Quality Control Plan 2001 Page 5 of 5 Final 6/15/2001

102 APPENDIX H TTMS Inspection & Inventory Forms Traffic Monitoring Handbook Page 102

103 TTMS INSPECTION SHEET (DOT) Technician Date Certified: YES / NO Site Unit # Equip Type: DAW100, DAW200, DAW190, ADR-1000, ADR-3000, ADR WIM, TC241a, TT2001, Phoenix, RTMS Program: Count, Speed, Class, WM, Class & Speed, Class by Speed NH Number Serial Number Phone Operational : YES / NO Speed Limit: N / E S / W Number of Lanes Time Zone: Sensor Configuration: None, L, LL, LPL, PLP, WPD, WPZ Sensor Mount: Surface, Below Friction Course Loop Length ft Sensor Spacing ft Modem Type: Qblazer, Microcom, LPM14E, Starcomm Warning Sign Installed: YES / NO Baud Rate Register Interval No. solar panels: Total Wattage: Power Circle one: SUNNY / CLOUDY Solar Output Voltage: Solar Regulator Output Voltage: Mast Type: Concrete, Aluminum, Wood, PT 4X4, Structure, None Cabinet Type: RR, 334, 3, 4, 5 Cabinet Mount: Low Base, High Base, Breakaway, Pole Wiring Harness: None, 36 Pin, 26 Pin, PAT Backplane: Tomlinson, FDOT(Walton), Peek, Pat, Control Specialists Total # of batteries Battery Voltage (under load): Battery size Battery type Ground Rod Resistance ohms Type of Suppressors: Power None, Tomlinson, Edco, Peek Telephone None, Tomlinson, Edco, Peek, Citel Presence Sensors None, Tomlinson, Edco, Peek Axle Sensors None, Tomlinson, Edco, Peek Weigh Pads None, Tomlinson, Edco, Pat Lane Designation: Lane 1 N,S,E,W - In, Out, Center, Center Left, Center Right Lane 2 N,S,E,W - In, Out, Center, Center Left, Center Right Lane 3 N,S,E,W - In, Out, Center, Center Left, Center Right Lane 4 N,S,E,W - In, Out, Center, Center Left, Center Right Lane 5 N,S,E,W - In, Out, Center, Center Left, Center Right Lane 6 N,S,E,W - In, Out, Center, Center Left, Center Right Lane 7 N,S,E,W - In, Out, Center, Center Left, Center Right Lane 8 N,S,E,W - In, Out, Center, Center Left, Center Right Piezo Brand: Mitron, Phillips, BL, Fiber-Optic, KISTLER, AtoChem, Insulation Meg Ohm: Loop Resistance: Piezo Voltage: WIM Piezo Voltage: Lane 1 Loop 1 Lane 1 #1 #2 #3 #4 Loop 2 Lane 2 Loop 3 Lane 2 #1 #2 #3 #4 Loop 4 Lane 3 Loop 5 Lane 3 #1 #2 #3 #4 Loop 6 Lane 4 Loop 7 Lane 4 #1 #2 #3 #4 Loop 8 Lane 5 Loop 9 Lane 5 #1 #2 #3 #4 Loop 10 Lane 6 Loop 11 Lane 6 #1 #2 #3 #4 Loop 12 Operational Check: Speed Counts Classification Weight Comments: 7/14/03

104 TTMS INVENTORY Date: Inspector: Site Unit 1 / 2 NH Nmbr: Speed Limit N / E S / W Warning Signs? Y / N Unit Model No. of Lanes Program Count, Speed, Class, WM, Class & Speed, Class by Speed Poll? Y / N / Download only Time Zone E / C Register interval Sensor Config L, P, L/L, P/L/P, L/P/L, WIM/PZ, WIM/BP Sensor Spacing ft. Loop Length ft. Modem Type Baud rate Power S / AC No. of Batteries Solar Panel Brand Battery Size amp hrs Nmbr of Panels Battery Type Gell, Lithium hydroxide, Total Wattage Mast Type None, Concrete, Aluminum, Wood, PT 4X4, Structure/Sign Cabinet Type R/R, 334, 3, 4, 5 Cabinet Mount Low Base, High Base, Breakaway, Pole Wire Harness None, 36 Pin, 26 Pin, PAT Back Plane None, Tomlinson, FDOT(Walton), Peek, Pat, Control Specialists Piezo Brand Mitron, Phillips, BL, KISLER, AtoChem Surge Suppression Power Telephone Presence Sensor Piezo Sensor Weigh Pad None, Tomlinson, Edco, Peek None, Tomlinson, Edco, Peek, Citel None, Tomlinson, Edco, Peek, Diamond None, Tomlinson, Edco, Peek None, Tomlinson, Edco, Peek Certified by: for Counts Class Class 2 Class 5 Class 9 Class Class Quantity by Class per Lane Lane Comments: Time: From: To: 1/4/2002